Merge remote-tracking branch 'upstream/master' into feat-cow-infra

`tests/wpt/web-platform-tests/html/browsers/origin/cross-origin-objects/cross-origin-objects.html`
was reverted to the upstream version.

21 files changed, 1588 insertions, 0 deletions

diff --git a/components/script/dom/webgl_extensions/ext/angleinstancedarrays.rs b/components/script/dom/webgl_extensions/ext/angleinstancedarrays.rs
new file mode 100644
index 00000000000..4d03f25781b
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/angleinstancedarrays.rs
@@ -0,0 +1,92 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::codegen::Bindings::ANGLEInstancedArraysBinding::ANGLEInstancedArraysConstants;
+use crate::dom::bindings::codegen::Bindings::ANGLEInstancedArraysBinding::ANGLEInstancedArraysMethods;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::{Dom, DomRoot};
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::WebGLVersion;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct ANGLEInstancedArrays {
+    reflector_: Reflector,
+    ctx: Dom<WebGLRenderingContext>,
+}
+
+impl ANGLEInstancedArrays {
+    fn new_inherited(ctx: &WebGLRenderingContext) -> Self {
+        Self {
+            reflector_: Reflector::new(),
+            ctx: Dom::from_ref(ctx),
+        }
+    }
+}
+
+impl WebGLExtension for ANGLEInstancedArrays {
+    type Extension = Self;
+
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<Self> {
+        reflect_dom_object(
+            Box::new(ANGLEInstancedArrays::new_inherited(ctx)),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&[
+            "GL_ANGLE_instanced_arrays",
+            "GL_ARB_instanced_arrays",
+            "GL_EXT_instanced_arrays",
+            "GL_NV_instanced_arrays",
+        ])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_get_vertex_attrib_name(
+            ANGLEInstancedArraysConstants::VERTEX_ATTRIB_ARRAY_DIVISOR_ANGLE,
+        );
+    }
+
+    fn name() -> &'static str {
+        "ANGLE_instanced_arrays"
+    }
+}
+
+impl ANGLEInstancedArraysMethods for ANGLEInstancedArrays {
+    // https://www.khronos.org/registry/webgl/extensions/ANGLE_instanced_arrays/
+    fn DrawArraysInstancedANGLE(&self, mode: u32, first: i32, count: i32, primcount: i32) {
+        handle_potential_webgl_error!(
+            self.ctx,
+            self.ctx
+                .draw_arrays_instanced(mode, first, count, primcount)
+        )
+    }
+
+    // https://www.khronos.org/registry/webgl/extensions/ANGLE_instanced_arrays/
+    fn DrawElementsInstancedANGLE(
+        &self,
+        mode: u32,
+        count: i32,
+        type_: u32,
+        offset: i64,
+        primcount: i32,
+    ) {
+        handle_potential_webgl_error!(
+            self.ctx,
+            self.ctx
+                .draw_elements_instanced(mode, count, type_, offset, primcount)
+        )
+    }
+
+    fn VertexAttribDivisorANGLE(&self, index: u32, divisor: u32) {
+        self.ctx.vertex_attrib_divisor(index, divisor);
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/extblendminmax.rs b/components/script/dom/webgl_extensions/ext/extblendminmax.rs
new file mode 100644
index 00000000000..122aac6c861
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/extblendminmax.rs
@@ -0,0 +1,47 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::WebGLVersion;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct EXTBlendMinmax {
+    reflector_: Reflector,
+}
+
+impl EXTBlendMinmax {
+    fn new_inherited() -> Self {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for EXTBlendMinmax {
+    type Extension = Self;
+
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<Self> {
+        reflect_dom_object(Box::new(Self::new_inherited()), &*ctx.global())
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_gl_extension("GL_EXT_blend_minmax")
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_blend_minmax();
+    }
+
+    fn name() -> &'static str {
+        "EXT_blend_minmax"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/extcolorbufferhalffloat.rs b/components/script/dom/webgl_extensions/ext/extcolorbufferhalffloat.rs
new file mode 100644
index 00000000000..bb4a630d537
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/extcolorbufferhalffloat.rs
@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webgl_extensions::ext::oestexturehalffloat::OESTextureHalfFloat;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::WebGLVersion;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct EXTColorBufferHalfFloat {
+    reflector_: Reflector,
+}
+
+impl EXTColorBufferHalfFloat {
+    fn new_inherited() -> EXTColorBufferHalfFloat {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for EXTColorBufferHalfFloat {
+    type Extension = EXTColorBufferHalfFloat;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<EXTColorBufferHalfFloat> {
+        reflect_dom_object(
+            Box::new(EXTColorBufferHalfFloat::new_inherited()),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        OESTextureHalfFloat::is_supported(ext)
+    }
+
+    fn enable(_ext: &WebGLExtensions) {}
+
+    fn name() -> &'static str {
+        "EXT_color_buffer_half_float"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/extfragdepth.rs b/components/script/dom/webgl_extensions/ext/extfragdepth.rs
new file mode 100644
index 00000000000..182b30bf754
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/extfragdepth.rs
@@ -0,0 +1,62 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::{WebGLSLVersion, WebGLVersion};
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct EXTFragDepth {
+    reflector_: Reflector,
+}
+
+impl EXTFragDepth {
+    fn new_inherited() -> EXTFragDepth {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for EXTFragDepth {
+    type Extension = Self;
+
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<Self> {
+        reflect_dom_object(Box::new(Self::new_inherited()), &*ctx.global())
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        let min_glsl_version = if ext.is_gles() {
+            WebGLSLVersion { major: 3, minor: 0 }
+        } else {
+            WebGLSLVersion {
+                major: 1,
+                minor: 10,
+            }
+        };
+        match (
+            ext.is_gles(),
+            ext.is_min_glsl_version_satisfied(min_glsl_version),
+        ) {
+            // ANGLE's shader translator can't translate ESSL1 exts to ESSL3. (bug
+            // 1524804)
+            (true, true) => false,
+            (true, false) => ext.supports_gl_extension("GL_EXT_frag_depth"),
+            (false, is_min_glsl_version_satisfied) => is_min_glsl_version_satisfied,
+        }
+    }
+
+    fn enable(_ext: &WebGLExtensions) {}
+
+    fn name() -> &'static str {
+        "EXT_frag_depth"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/extshadertexturelod.rs b/components/script/dom/webgl_extensions/ext/extshadertexturelod.rs
new file mode 100644
index 00000000000..ea68b518dac
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/extshadertexturelod.rs
@@ -0,0 +1,46 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::WebGLVersion;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct EXTShaderTextureLod {
+    reflector_: Reflector,
+}
+
+impl EXTShaderTextureLod {
+    fn new_inherited() -> Self {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for EXTShaderTextureLod {
+    type Extension = Self;
+
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<Self> {
+        reflect_dom_object(Box::new(Self::new_inherited()), &*ctx.global())
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        // This extension is always available on desktop GL.
+        !ext.is_gles() || ext.supports_gl_extension("GL_EXT_shader_texture_lod")
+    }
+
+    fn enable(_ext: &WebGLExtensions) {}
+
+    fn name() -> &'static str {
+        "EXT_shader_texture_lod"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/exttexturefilteranisotropic.rs b/components/script/dom/webgl_extensions/ext/exttexturefilteranisotropic.rs
new file mode 100644
index 00000000000..89a4d3ed6a4
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/exttexturefilteranisotropic.rs
@@ -0,0 +1,53 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::codegen::Bindings::EXTTextureFilterAnisotropicBinding::EXTTextureFilterAnisotropicConstants;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::WebGLVersion;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct EXTTextureFilterAnisotropic {
+    reflector_: Reflector,
+}
+
+impl EXTTextureFilterAnisotropic {
+    fn new_inherited() -> EXTTextureFilterAnisotropic {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for EXTTextureFilterAnisotropic {
+    type Extension = EXTTextureFilterAnisotropic;
+
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<Self> {
+        reflect_dom_object(Box::new(Self::new_inherited()), &*ctx.global())
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_gl_extension("GL_EXT_texture_filter_anisotropic")
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_get_tex_parameter_name(
+            EXTTextureFilterAnisotropicConstants::TEXTURE_MAX_ANISOTROPY_EXT,
+        );
+        ext.enable_get_parameter_name(
+            EXTTextureFilterAnisotropicConstants::MAX_TEXTURE_MAX_ANISOTROPY_EXT,
+        );
+    }
+
+    fn name() -> &'static str {
+        "EXT_texture_filter_anisotropic"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/mod.rs b/components/script/dom/webgl_extensions/ext/mod.rs
new file mode 100644
index 00000000000..229d09d56f5
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/mod.rs
@@ -0,0 +1,23 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
+
+pub mod angleinstancedarrays;
+pub mod extblendminmax;
+pub mod extcolorbufferhalffloat;
+pub mod extfragdepth;
+pub mod extshadertexturelod;
+pub mod exttexturefilteranisotropic;
+pub mod oeselementindexuint;
+pub mod oesstandardderivatives;
+pub mod oestexturefloat;
+pub mod oestexturefloatlinear;
+pub mod oestexturehalffloat;
+pub mod oestexturehalffloatlinear;
+pub mod oesvertexarrayobject;
+pub mod webglcolorbufferfloat;
+pub mod webglcompressedtextureetc1;
+pub mod webglcompressedtextures3tc;
diff --git a/components/script/dom/webgl_extensions/ext/oeselementindexuint.rs b/components/script/dom/webgl_extensions/ext/oeselementindexuint.rs
new file mode 100644
index 00000000000..096c22d3dc5
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/oeselementindexuint.rs
@@ -0,0 +1,51 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::WebGLVersion;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct OESElementIndexUint {
+    reflector_: Reflector,
+}
+
+impl OESElementIndexUint {
+    fn new_inherited() -> Self {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESElementIndexUint {
+    type Extension = Self;
+
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<Self> {
+        reflect_dom_object(
+            Box::new(OESElementIndexUint::new_inherited()),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        // This extension is always available in desktop OpenGL.
+        !ext.is_gles() || ext.supports_gl_extension("GL_OES_element_index_uint")
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_element_index_uint();
+    }
+
+    fn name() -> &'static str {
+        "OES_element_index_uint"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs b/components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs
new file mode 100644
index 00000000000..dfafa7051a5
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs
@@ -0,0 +1,56 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::codegen::Bindings::OESStandardDerivativesBinding::OESStandardDerivativesConstants;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::WebGLVersion;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct OESStandardDerivatives {
+    reflector_: Reflector,
+}
+
+impl OESStandardDerivatives {
+    fn new_inherited() -> OESStandardDerivatives {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESStandardDerivatives {
+    type Extension = OESStandardDerivatives;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESStandardDerivatives> {
+        reflect_dom_object(
+            Box::new(OESStandardDerivatives::new_inherited()),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        // The standard derivatives are always available in desktop OpenGL.
+        !ext.is_gles() || ext.supports_any_gl_extension(&["GL_OES_standard_derivatives"])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_hint_target(
+            OESStandardDerivativesConstants::FRAGMENT_SHADER_DERIVATIVE_HINT_OES,
+        );
+        ext.enable_get_parameter_name(
+            OESStandardDerivativesConstants::FRAGMENT_SHADER_DERIVATIVE_HINT_OES,
+        );
+    }
+
+    fn name() -> &'static str {
+        "OES_standard_derivatives"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/oestexturefloat.rs b/components/script/dom/webgl_extensions/ext/oestexturefloat.rs
new file mode 100644
index 00000000000..e286095b7c7
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/oestexturefloat.rs
@@ -0,0 +1,63 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{constants as webgl, WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::{TexFormat, WebGLVersion};
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct OESTextureFloat {
+    reflector_: Reflector,
+}
+
+impl OESTextureFloat {
+    fn new_inherited() -> OESTextureFloat {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESTextureFloat {
+    type Extension = OESTextureFloat;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESTextureFloat> {
+        reflect_dom_object(Box::new(OESTextureFloat::new_inherited()), &*ctx.global())
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&[
+            "GL_OES_texture_float",
+            "GL_ARB_texture_float",
+            "GL_EXT_color_buffer_float",
+        ])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_tex_type(webgl::FLOAT);
+        ext.add_effective_tex_internal_format(TexFormat::RGBA, webgl::FLOAT, TexFormat::RGBA32f);
+        ext.add_effective_tex_internal_format(TexFormat::RGB, webgl::FLOAT, TexFormat::RGB32f);
+        ext.add_effective_tex_internal_format(
+            TexFormat::Luminance,
+            webgl::FLOAT,
+            TexFormat::Luminance32f,
+        );
+        ext.add_effective_tex_internal_format(TexFormat::Alpha, webgl::FLOAT, TexFormat::Alpha32f);
+        ext.add_effective_tex_internal_format(
+            TexFormat::LuminanceAlpha,
+            webgl::FLOAT,
+            TexFormat::LuminanceAlpha32f,
+        );
+    }
+
+    fn name() -> &'static str {
+        "OES_texture_float"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/oestexturefloatlinear.rs b/components/script/dom/webgl_extensions/ext/oestexturefloatlinear.rs
new file mode 100644
index 00000000000..9e5c021f0ef
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/oestexturefloatlinear.rs
@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{constants as webgl, WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct OESTextureFloatLinear {
+    reflector_: Reflector,
+}
+
+impl OESTextureFloatLinear {
+    fn new_inherited() -> OESTextureFloatLinear {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESTextureFloatLinear {
+    type Extension = OESTextureFloatLinear;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESTextureFloatLinear> {
+        reflect_dom_object(
+            Box::new(OESTextureFloatLinear::new_inherited()),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::All
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&["GL_OES_texture_float_linear", "GL_ARB_texture_float"])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_filterable_tex_type(webgl::FLOAT);
+    }
+
+    fn name() -> &'static str {
+        "OES_texture_float_linear"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/oestexturehalffloat.rs b/components/script/dom/webgl_extensions/ext/oestexturehalffloat.rs
new file mode 100644
index 00000000000..4f2ef41c651
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/oestexturehalffloat.rs
@@ -0,0 +1,65 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::codegen::Bindings::OESTextureHalfFloatBinding::OESTextureHalfFloatConstants;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::{TexFormat, WebGLVersion};
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct OESTextureHalfFloat {
+    reflector_: Reflector,
+}
+
+impl OESTextureHalfFloat {
+    fn new_inherited() -> OESTextureHalfFloat {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESTextureHalfFloat {
+    type Extension = OESTextureHalfFloat;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESTextureHalfFloat> {
+        reflect_dom_object(
+            Box::new(OESTextureHalfFloat::new_inherited()),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&[
+            "GL_OES_texture_half_float",
+            "GL_ARB_half_float_pixel",
+            "GL_NV_half_float",
+            "GL_EXT_color_buffer_half_float",
+        ])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        let hf = OESTextureHalfFloatConstants::HALF_FLOAT_OES;
+        ext.enable_tex_type(hf);
+        ext.add_effective_tex_internal_format(TexFormat::RGBA, hf, TexFormat::RGBA16f);
+        ext.add_effective_tex_internal_format(TexFormat::RGB, hf, TexFormat::RGB16f);
+        ext.add_effective_tex_internal_format(TexFormat::Luminance, hf, TexFormat::Luminance16f);
+        ext.add_effective_tex_internal_format(TexFormat::Alpha, hf, TexFormat::Alpha16f);
+        ext.add_effective_tex_internal_format(
+            TexFormat::LuminanceAlpha,
+            hf,
+            TexFormat::LuminanceAlpha16f,
+        );
+    }
+
+    fn name() -> &'static str {
+        "OES_texture_half_float"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/oestexturehalffloatlinear.rs b/components/script/dom/webgl_extensions/ext/oestexturehalffloatlinear.rs
new file mode 100644
index 00000000000..a1e5f3bf15d
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/oestexturehalffloatlinear.rs
@@ -0,0 +1,53 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::codegen::Bindings::OESTextureHalfFloatBinding::OESTextureHalfFloatConstants;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct OESTextureHalfFloatLinear {
+    reflector_: Reflector,
+}
+
+impl OESTextureHalfFloatLinear {
+    fn new_inherited() -> OESTextureHalfFloatLinear {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESTextureHalfFloatLinear {
+    type Extension = OESTextureHalfFloatLinear;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESTextureHalfFloatLinear> {
+        reflect_dom_object(
+            Box::new(OESTextureHalfFloatLinear::new_inherited()),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::All
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&[
+            "GL_OES_texture_float_linear",
+            "GL_ARB_half_float_pixel",
+            "GL_NV_half_float",
+        ])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_filterable_tex_type(OESTextureHalfFloatConstants::HALF_FLOAT_OES);
+    }
+
+    fn name() -> &'static str {
+        "OES_texture_half_float_linear"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/oesvertexarrayobject.rs b/components/script/dom/webgl_extensions/ext/oesvertexarrayobject.rs
new file mode 100644
index 00000000000..57a68142609
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/oesvertexarrayobject.rs
@@ -0,0 +1,80 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::codegen::Bindings::OESVertexArrayObjectBinding::OESVertexArrayObjectConstants;
+use crate::dom::bindings::codegen::Bindings::OESVertexArrayObjectBinding::OESVertexArrayObjectMethods;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::{Dom, DomRoot};
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use crate::dom::webglvertexarrayobjectoes::WebGLVertexArrayObjectOES;
+use canvas_traits::webgl::WebGLVersion;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct OESVertexArrayObject {
+    reflector_: Reflector,
+    ctx: Dom<WebGLRenderingContext>,
+}
+
+impl OESVertexArrayObject {
+    fn new_inherited(ctx: &WebGLRenderingContext) -> OESVertexArrayObject {
+        Self {
+            reflector_: Reflector::new(),
+            ctx: Dom::from_ref(ctx),
+        }
+    }
+}
+
+impl OESVertexArrayObjectMethods for OESVertexArrayObject {
+    // https://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
+    fn CreateVertexArrayOES(&self) -> Option<DomRoot<WebGLVertexArrayObjectOES>> {
+        self.ctx.create_vertex_array()
+    }
+
+    // https://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
+    fn DeleteVertexArrayOES(&self, vao: Option<&WebGLVertexArrayObjectOES>) {
+        self.ctx.delete_vertex_array(vao);
+    }
+
+    // https://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
+    fn IsVertexArrayOES(&self, vao: Option<&WebGLVertexArrayObjectOES>) -> bool {
+        self.ctx.is_vertex_array(vao)
+    }
+
+    // https://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
+    fn BindVertexArrayOES(&self, vao: Option<&WebGLVertexArrayObjectOES>) {
+        self.ctx.bind_vertex_array(vao);
+    }
+}
+
+impl WebGLExtension for OESVertexArrayObject {
+    type Extension = OESVertexArrayObject;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<OESVertexArrayObject> {
+        reflect_dom_object(
+            Box::new(OESVertexArrayObject::new_inherited(ctx)),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&[
+            "GL_OES_vertex_array_object",
+            "GL_ARB_vertex_array_object",
+            "GL_APPLE_vertex_array_object",
+        ])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_get_parameter_name(OESVertexArrayObjectConstants::VERTEX_ARRAY_BINDING_OES);
+    }
+
+    fn name() -> &'static str {
+        "OES_vertex_array_object"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/webglcolorbufferfloat.rs b/components/script/dom/webgl_extensions/ext/webglcolorbufferfloat.rs
new file mode 100644
index 00000000000..c0d8dc13776
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/webglcolorbufferfloat.rs
@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webgl_extensions::ext::oestexturefloat::OESTextureFloat;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::WebGLVersion;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct WEBGLColorBufferFloat {
+    reflector_: Reflector,
+}
+
+impl WEBGLColorBufferFloat {
+    fn new_inherited() -> WEBGLColorBufferFloat {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for WEBGLColorBufferFloat {
+    type Extension = WEBGLColorBufferFloat;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<WEBGLColorBufferFloat> {
+        reflect_dom_object(
+            Box::new(WEBGLColorBufferFloat::new_inherited()),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        OESTextureFloat::is_supported(ext)
+    }
+
+    fn enable(_ext: &WebGLExtensions) {}
+
+    fn name() -> &'static str {
+        "WEBGL_color_buffer_float"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/webglcompressedtextureetc1.rs b/components/script/dom/webgl_extensions/ext/webglcompressedtextureetc1.rs
new file mode 100644
index 00000000000..749c38abd82
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/webglcompressedtextureetc1.rs
@@ -0,0 +1,56 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use crate::dom::webgltexture::{TexCompression, TexCompressionValidation};
+use canvas_traits::webgl::{TexFormat, WebGLVersion};
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct WEBGLCompressedTextureETC1 {
+    reflector_: Reflector,
+}
+
+impl WEBGLCompressedTextureETC1 {
+    fn new_inherited() -> WEBGLCompressedTextureETC1 {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for WEBGLCompressedTextureETC1 {
+    type Extension = WEBGLCompressedTextureETC1;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<WEBGLCompressedTextureETC1> {
+        reflect_dom_object(
+            Box::new(WEBGLCompressedTextureETC1::new_inherited()),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_gl_extension("GL_OES_compressed_ETC1_RGB8_texture")
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.add_tex_compression_formats(&[TexCompression {
+            format: TexFormat::CompressedRgbEtc1,
+            bytes_per_block: 8,
+            block_width: 4,
+            block_height: 4,
+            validation: TexCompressionValidation::None,
+        }]);
+    }
+
+    fn name() -> &'static str {
+        "WEBGL_compressed_texture_etc1"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/ext/webglcompressedtextures3tc.rs b/components/script/dom/webgl_extensions/ext/webglcompressedtextures3tc.rs
new file mode 100644
index 00000000000..362dbe67117
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/webglcompressedtextures3tc.rs
@@ -0,0 +1,84 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use crate::dom::webgltexture::{TexCompression, TexCompressionValidation};
+use canvas_traits::webgl::{TexFormat, WebGLVersion};
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct WEBGLCompressedTextureS3TC {
+    reflector_: Reflector,
+}
+
+impl WEBGLCompressedTextureS3TC {
+    fn new_inherited() -> WEBGLCompressedTextureS3TC {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for WEBGLCompressedTextureS3TC {
+    type Extension = WEBGLCompressedTextureS3TC;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<WEBGLCompressedTextureS3TC> {
+        reflect_dom_object(
+            Box::new(WEBGLCompressedTextureS3TC::new_inherited()),
+            &*ctx.global(),
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_gl_extension("GL_EXT_texture_compression_s3tc") ||
+            ext.supports_all_gl_extension(&[
+                "GL_EXT_texture_compression_dxt1",
+                "GL_ANGLE_texture_compression_dxt3",
+                "GL_ANGLE_texture_compression_dxt5",
+            ])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.add_tex_compression_formats(&[
+            TexCompression {
+                format: TexFormat::CompressedRgbS3tcDxt1,
+                bytes_per_block: 8,
+                block_width: 4,
+                block_height: 4,
+                validation: TexCompressionValidation::S3TC,
+            },
+            TexCompression {
+                format: TexFormat::CompressedRgbaS3tcDxt1,
+                bytes_per_block: 8,
+                block_width: 4,
+                block_height: 4,
+                validation: TexCompressionValidation::S3TC,
+            },
+            TexCompression {
+                format: TexFormat::CompressedRgbaS3tcDxt3,
+                bytes_per_block: 16,
+                block_width: 4,
+                block_height: 4,
+                validation: TexCompressionValidation::S3TC,
+            },
+            TexCompression {
+                format: TexFormat::CompressedRgbaS3tcDxt5,
+                bytes_per_block: 16,
+                block_width: 4,
+                block_height: 4,
+                validation: TexCompressionValidation::S3TC,
+            },
+        ]);
+    }
+
+    fn name() -> &'static str {
+        "WEBGL_compressed_texture_s3tc"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/extension.rs b/components/script/dom/webgl_extensions/extension.rs
new file mode 100644
index 00000000000..3854acee122
--- /dev/null
+++ b/components/script/dom/webgl_extensions/extension.rs
@@ -0,0 +1,40 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::WebGLExtensions;
+use crate::dom::bindings::reflector::DomObject;
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::bindings::trace::JSTraceable;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use canvas_traits::webgl::WebGLVersion;
+
+/// Trait implemented by WebGL extensions.
+pub trait WebGLExtension: Sized
+where
+    Self::Extension: DomObject + JSTraceable,
+{
+    type Extension;
+
+    /// Creates the DOM object of the WebGL extension.
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<Self::Extension>;
+
+    /// Returns which WebGL spec is this extension written against.
+    fn spec() -> WebGLExtensionSpec;
+
+    /// Checks if the extension is supported.
+    fn is_supported(ext: &WebGLExtensions) -> bool;
+
+    /// Enable the extension.
+    fn enable(ext: &WebGLExtensions);
+
+    /// Name of the WebGL Extension.
+    fn name() -> &'static str;
+}
+
+pub enum WebGLExtensionSpec {
+    /// Extensions written against both WebGL and WebGL2 specs.
+    All,
+    /// Extensions writen against a specific WebGL version spec.
+    Specific(WebGLVersion),
+}
diff --git a/components/script/dom/webgl_extensions/extensions.rs b/components/script/dom/webgl_extensions/extensions.rs
new file mode 100644
index 00000000000..97e5900960f
--- /dev/null
+++ b/components/script/dom/webgl_extensions/extensions.rs
@@ -0,0 +1,470 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::wrapper::{TypedWebGLExtensionWrapper, WebGLExtensionWrapper};
+use super::{ext, WebGLExtension, WebGLExtensionSpec};
+use crate::dom::bindings::cell::DomRefCell;
+use crate::dom::bindings::codegen::Bindings::ANGLEInstancedArraysBinding::ANGLEInstancedArraysConstants;
+use crate::dom::bindings::codegen::Bindings::EXTTextureFilterAnisotropicBinding::EXTTextureFilterAnisotropicConstants;
+use crate::dom::bindings::codegen::Bindings::OESStandardDerivativesBinding::OESStandardDerivativesConstants;
+use crate::dom::bindings::codegen::Bindings::OESTextureHalfFloatBinding::OESTextureHalfFloatConstants;
+use crate::dom::bindings::codegen::Bindings::OESVertexArrayObjectBinding::OESVertexArrayObjectConstants;
+use crate::dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
+use crate::dom::bindings::trace::JSTraceable;
+use crate::dom::extcolorbufferhalffloat::EXTColorBufferHalfFloat;
+use crate::dom::oestexturefloat::OESTextureFloat;
+use crate::dom::oestexturehalffloat::OESTextureHalfFloat;
+use crate::dom::webglcolorbufferfloat::WEBGLColorBufferFloat;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use crate::dom::webgltexture::TexCompression;
+use canvas_traits::webgl::{GlType, TexFormat, WebGLSLVersion, WebGLVersion};
+use fnv::{FnvHashMap, FnvHashSet};
+use js::jsapi::JSObject;
+use malloc_size_of::MallocSizeOf;
+use sparkle::gl::{self, GLenum};
+use std::collections::HashMap;
+use std::iter::FromIterator;
+use std::ptr::NonNull;
+
+// Data types that are implemented for texImage2D and texSubImage2D in a WebGL 1.0 context
+// but must trigger a InvalidValue error until the related WebGL Extensions are enabled.
+// Example: https://www.khronos.org/registry/webgl/extensions/OES_texture_float/
+const DEFAULT_DISABLED_TEX_TYPES_WEBGL1: [GLenum; 2] = [
+    constants::FLOAT,
+    OESTextureHalfFloatConstants::HALF_FLOAT_OES,
+];
+
+// Data types that are implemented for textures in WebGLRenderingContext
+// but not allowed to use with linear filtering until the related WebGL Extensions are enabled.
+// Example: https://www.khronos.org/registry/webgl/extensions/OES_texture_float_linear/
+const DEFAULT_NOT_FILTERABLE_TEX_TYPES: [GLenum; 2] = [
+    constants::FLOAT,
+    OESTextureHalfFloatConstants::HALF_FLOAT_OES,
+];
+
+// Param names that are implemented for glGetParameter in a WebGL 1.0 context
+// but must trigger a InvalidEnum error until the related WebGL Extensions are enabled.
+// Example: https://www.khronos.org/registry/webgl/extensions/OES_standard_derivatives/
+const DEFAULT_DISABLED_GET_PARAMETER_NAMES_WEBGL1: [GLenum; 3] = [
+    EXTTextureFilterAnisotropicConstants::MAX_TEXTURE_MAX_ANISOTROPY_EXT,
+    OESStandardDerivativesConstants::FRAGMENT_SHADER_DERIVATIVE_HINT_OES,
+    OESVertexArrayObjectConstants::VERTEX_ARRAY_BINDING_OES,
+];
+
+// Param names that are implemented for glGetParameter in a WebGL 2.0 context
+// but must trigger a InvalidEnum error until the related WebGL Extensions are enabled.
+// Example: https://www.khronos.org/registry/webgl/extensions/EXT_texture_filter_anisotropic/
+const DEFAULT_DISABLED_GET_PARAMETER_NAMES_WEBGL2: [GLenum; 1] =
+    [EXTTextureFilterAnisotropicConstants::MAX_TEXTURE_MAX_ANISOTROPY_EXT];
+
+// Param names that are implemented for glGetTexParameter in a WebGL 1.0 context
+// but must trigger a InvalidEnum error until the related WebGL Extensions are enabled.
+// Example: https://www.khronos.org/registry/webgl/extensions/OES_standard_derivatives/
+const DEFAULT_DISABLED_GET_TEX_PARAMETER_NAMES_WEBGL1: [GLenum; 1] =
+    [EXTTextureFilterAnisotropicConstants::TEXTURE_MAX_ANISOTROPY_EXT];
+
+// Param names that are implemented for glGetTexParameter in a WebGL 2.0 context
+// but must trigger a InvalidEnum error until the related WebGL Extensions are enabled.
+// Example: https://www.khronos.org/registry/webgl/extensions/EXT_texture_filter_anisotropic/
+const DEFAULT_DISABLED_GET_TEX_PARAMETER_NAMES_WEBGL2: [GLenum; 1] =
+    [EXTTextureFilterAnisotropicConstants::TEXTURE_MAX_ANISOTROPY_EXT];
+
+// Param names that are implemented for glGetVertexAttrib in a WebGL 1.0 context
+// but must trigger a InvalidEnum error until the related WebGL Extensions are enabled.
+// Example: https://www.khronos.org/registry/webgl/extensions/ANGLE_instanced_arrays/
+const DEFAULT_DISABLED_GET_VERTEX_ATTRIB_NAMES_WEBGL1: [GLenum; 1] =
+    [ANGLEInstancedArraysConstants::VERTEX_ATTRIB_ARRAY_DIVISOR_ANGLE];
+
+/// WebGL features that are enabled/disabled by WebGL Extensions.
+#[derive(JSTraceable, MallocSizeOf)]
+struct WebGLExtensionFeatures {
+    gl_extensions: FnvHashSet<String>,
+    disabled_tex_types: FnvHashSet<GLenum>,
+    not_filterable_tex_types: FnvHashSet<GLenum>,
+    effective_tex_internal_formats: FnvHashMap<TexFormatType, TexFormat>,
+    /// WebGL Hint() targets enabled by extensions.
+    hint_targets: FnvHashSet<GLenum>,
+    /// WebGL GetParameter() names enabled by extensions.
+    disabled_get_parameter_names: FnvHashSet<GLenum>,
+    /// WebGL GetTexParameter() names enabled by extensions.
+    disabled_get_tex_parameter_names: FnvHashSet<GLenum>,
+    /// WebGL GetAttribVertex() names enabled by extensions.
+    disabled_get_vertex_attrib_names: FnvHashSet<GLenum>,
+    /// WebGL OES_element_index_uint extension.
+    element_index_uint_enabled: bool,
+    /// WebGL EXT_blend_minmax extension.
+    blend_minmax_enabled: bool,
+    /// WebGL supported texture compression formats enabled by extensions.
+    tex_compression_formats: FnvHashMap<GLenum, TexCompression>,
+}
+
+impl WebGLExtensionFeatures {
+    fn new(webgl_version: WebGLVersion) -> Self {
+        let (
+            disabled_tex_types,
+            disabled_get_parameter_names,
+            disabled_get_tex_parameter_names,
+            disabled_get_vertex_attrib_names,
+            not_filterable_tex_types,
+            element_index_uint_enabled,
+            blend_minmax_enabled,
+        ) = match webgl_version {
+            WebGLVersion::WebGL1 => (
+                DEFAULT_DISABLED_TEX_TYPES_WEBGL1.iter().cloned().collect(),
+                DEFAULT_DISABLED_GET_PARAMETER_NAMES_WEBGL1
+                    .iter()
+                    .cloned()
+                    .collect(),
+                DEFAULT_DISABLED_GET_TEX_PARAMETER_NAMES_WEBGL1
+                    .iter()
+                    .cloned()
+                    .collect(),
+                DEFAULT_DISABLED_GET_VERTEX_ATTRIB_NAMES_WEBGL1
+                    .iter()
+                    .cloned()
+                    .collect(),
+                DEFAULT_NOT_FILTERABLE_TEX_TYPES.iter().cloned().collect(),
+                false,
+                false,
+            ),
+            WebGLVersion::WebGL2 => (
+                Default::default(),
+                DEFAULT_DISABLED_GET_PARAMETER_NAMES_WEBGL2
+                    .iter()
+                    .cloned()
+                    .collect(),
+                DEFAULT_DISABLED_GET_TEX_PARAMETER_NAMES_WEBGL2
+                    .iter()
+                    .cloned()
+                    .collect(),
+                Default::default(),
+                Default::default(),
+                true,
+                true,
+            ),
+        };
+        Self {
+            gl_extensions: Default::default(),
+            disabled_tex_types,
+            not_filterable_tex_types,
+            effective_tex_internal_formats: Default::default(),
+            hint_targets: Default::default(),
+            disabled_get_parameter_names,
+            disabled_get_tex_parameter_names,
+            disabled_get_vertex_attrib_names,
+            element_index_uint_enabled,
+            blend_minmax_enabled,
+            tex_compression_formats: Default::default(),
+        }
+    }
+}
+
+/// Handles the list of implemented, supported and enabled WebGL extensions.
+#[unrooted_must_root_lint::must_root]
+#[derive(JSTraceable, MallocSizeOf)]
+pub struct WebGLExtensions {
+    extensions: DomRefCell<HashMap<String, Box<dyn WebGLExtensionWrapper>>>,
+    features: DomRefCell<WebGLExtensionFeatures>,
+    webgl_version: WebGLVersion,
+    api_type: GlType,
+    glsl_version: WebGLSLVersion,
+}
+
+impl WebGLExtensions {
+    pub fn new(
+        webgl_version: WebGLVersion,
+        api_type: GlType,
+        glsl_version: WebGLSLVersion,
+    ) -> WebGLExtensions {
+        Self {
+            extensions: DomRefCell::new(HashMap::new()),
+            features: DomRefCell::new(WebGLExtensionFeatures::new(webgl_version)),
+            webgl_version,
+            api_type,
+            glsl_version,
+        }
+    }
+
+    pub fn init_once<F>(&self, cb: F)
+    where
+        F: FnOnce() -> String,
+    {
+        if self.extensions.borrow().len() == 0 {
+            let gl_str = cb();
+            self.features.borrow_mut().gl_extensions =
+                FnvHashSet::from_iter(gl_str.split(&[',', ' '][..]).map(|s| s.into()));
+            self.register_all_extensions();
+        }
+    }
+
+    pub fn register<T: 'static + WebGLExtension + JSTraceable + MallocSizeOf>(&self) {
+        let name = T::name().to_uppercase();
+        self.extensions
+            .borrow_mut()
+            .insert(name, Box::new(TypedWebGLExtensionWrapper::<T>::new()));
+    }
+
+    pub fn get_supported_extensions(&self) -> Vec<&'static str> {
+        self.extensions
+            .borrow()
+            .iter()
+            .filter(|ref v| {
+                if let WebGLExtensionSpec::Specific(version) = v.1.spec() {
+                    if self.webgl_version != version {
+                        return false;
+                    }
+                }
+                v.1.is_supported(&self)
+            })
+            .map(|ref v| v.1.name())
+            .collect()
+    }
+
+    pub fn get_or_init_extension(
+        &self,
+        name: &str,
+        ctx: &WebGLRenderingContext,
+    ) -> Option<NonNull<JSObject>> {
+        let name = name.to_uppercase();
+        self.extensions.borrow().get(&name).and_then(|extension| {
+            if extension.is_supported(self) {
+                Some(extension.instance_or_init(ctx, self))
+            } else {
+                None
+            }
+        })
+    }
+
+    pub fn is_enabled<T>(&self) -> bool
+    where
+        T: 'static + WebGLExtension + JSTraceable + MallocSizeOf,
+    {
+        let name = T::name().to_uppercase();
+        self.extensions
+            .borrow()
+            .get(&name)
+            .map_or(false, |ext| ext.is_enabled())
+    }
+
+    pub fn supports_gl_extension(&self, name: &str) -> bool {
+        self.features.borrow().gl_extensions.contains(name)
+    }
+
+    pub fn supports_any_gl_extension(&self, names: &[&str]) -> bool {
+        let features = self.features.borrow();
+        names
+            .iter()
+            .any(|name| features.gl_extensions.contains(*name))
+    }
+
+    pub fn supports_all_gl_extension(&self, names: &[&str]) -> bool {
+        let features = self.features.borrow();
+        names
+            .iter()
+            .all(|name| features.gl_extensions.contains(*name))
+    }
+
+    pub fn enable_tex_type(&self, data_type: GLenum) {
+        self.features
+            .borrow_mut()
+            .disabled_tex_types
+            .remove(&data_type);
+    }
+
+    pub fn is_tex_type_enabled(&self, data_type: GLenum) -> bool {
+        self.features
+            .borrow()
+            .disabled_tex_types
+            .get(&data_type)
+            .is_none()
+    }
+
+    pub fn add_effective_tex_internal_format(
+        &self,
+        source_internal_format: TexFormat,
+        source_data_type: u32,
+        effective_internal_format: TexFormat,
+    ) {
+        let format = TexFormatType(source_internal_format, source_data_type);
+        self.features
+            .borrow_mut()
+            .effective_tex_internal_formats
+            .insert(format, effective_internal_format);
+    }
+
+    pub fn get_effective_tex_internal_format(
+        &self,
+        source_internal_format: TexFormat,
+        source_data_type: u32,
+    ) -> TexFormat {
+        let format = TexFormatType(source_internal_format, source_data_type);
+        *(self
+            .features
+            .borrow()
+            .effective_tex_internal_formats
+            .get(&format)
+            .unwrap_or(&source_internal_format))
+    }
+
+    pub fn enable_filterable_tex_type(&self, text_data_type: GLenum) {
+        self.features
+            .borrow_mut()
+            .not_filterable_tex_types
+            .remove(&text_data_type);
+    }
+
+    pub fn is_filterable(&self, text_data_type: u32) -> bool {
+        self.features
+            .borrow()
+            .not_filterable_tex_types
+            .get(&text_data_type)
+            .is_none()
+    }
+
+    pub fn enable_hint_target(&self, name: GLenum) {
+        self.features.borrow_mut().hint_targets.insert(name);
+    }
+
+    pub fn is_hint_target_enabled(&self, name: GLenum) -> bool {
+        self.features.borrow().hint_targets.contains(&name)
+    }
+
+    pub fn enable_get_parameter_name(&self, name: GLenum) {
+        self.features
+            .borrow_mut()
+            .disabled_get_parameter_names
+            .remove(&name);
+    }
+
+    pub fn is_get_parameter_name_enabled(&self, name: GLenum) -> bool {
+        !self
+            .features
+            .borrow()
+            .disabled_get_parameter_names
+            .contains(&name)
+    }
+
+    pub fn enable_get_tex_parameter_name(&self, name: GLenum) {
+        self.features
+            .borrow_mut()
+            .disabled_get_tex_parameter_names
+            .remove(&name);
+    }
+
+    pub fn is_get_tex_parameter_name_enabled(&self, name: GLenum) -> bool {
+        !self
+            .features
+            .borrow()
+            .disabled_get_tex_parameter_names
+            .contains(&name)
+    }
+
+    pub fn enable_get_vertex_attrib_name(&self, name: GLenum) {
+        self.features
+            .borrow_mut()
+            .disabled_get_vertex_attrib_names
+            .remove(&name);
+    }
+
+    pub fn is_get_vertex_attrib_name_enabled(&self, name: GLenum) -> bool {
+        !self
+            .features
+            .borrow()
+            .disabled_get_vertex_attrib_names
+            .contains(&name)
+    }
+
+    pub fn add_tex_compression_formats(&self, formats: &[TexCompression]) {
+        let formats: FnvHashMap<GLenum, TexCompression> = formats
+            .iter()
+            .map(|&compression| (compression.format.as_gl_constant(), compression))
+            .collect();
+
+        self.features
+            .borrow_mut()
+            .tex_compression_formats
+            .extend(formats.iter());
+    }
+
+    pub fn get_tex_compression_format(&self, format_id: GLenum) -> Option<TexCompression> {
+        self.features
+            .borrow()
+            .tex_compression_formats
+            .get(&format_id)
+            .cloned()
+    }
+
+    pub fn get_tex_compression_ids(&self) -> Vec<GLenum> {
+        self.features
+            .borrow()
+            .tex_compression_formats
+            .keys()
+            .map(|&k| k)
+            .collect()
+    }
+
+    fn register_all_extensions(&self) {
+        self.register::<ext::angleinstancedarrays::ANGLEInstancedArrays>();
+        self.register::<ext::extblendminmax::EXTBlendMinmax>();
+        self.register::<ext::extcolorbufferhalffloat::EXTColorBufferHalfFloat>();
+        self.register::<ext::extfragdepth::EXTFragDepth>();
+        self.register::<ext::extshadertexturelod::EXTShaderTextureLod>();
+        self.register::<ext::exttexturefilteranisotropic::EXTTextureFilterAnisotropic>();
+        self.register::<ext::oeselementindexuint::OESElementIndexUint>();
+        self.register::<ext::oesstandardderivatives::OESStandardDerivatives>();
+        self.register::<ext::oestexturefloat::OESTextureFloat>();
+        self.register::<ext::oestexturefloatlinear::OESTextureFloatLinear>();
+        self.register::<ext::oestexturehalffloat::OESTextureHalfFloat>();
+        self.register::<ext::oestexturehalffloatlinear::OESTextureHalfFloatLinear>();
+        self.register::<ext::oesvertexarrayobject::OESVertexArrayObject>();
+        self.register::<ext::webglcolorbufferfloat::WEBGLColorBufferFloat>();
+        self.register::<ext::webglcompressedtextureetc1::WEBGLCompressedTextureETC1>();
+        self.register::<ext::webglcompressedtextures3tc::WEBGLCompressedTextureS3TC>();
+    }
+
+    pub fn enable_element_index_uint(&self) {
+        self.features.borrow_mut().element_index_uint_enabled = true;
+    }
+
+    pub fn is_element_index_uint_enabled(&self) -> bool {
+        self.features.borrow().element_index_uint_enabled
+    }
+
+    pub fn enable_blend_minmax(&self) {
+        self.features.borrow_mut().blend_minmax_enabled = true;
+    }
+
+    pub fn is_blend_minmax_enabled(&self) -> bool {
+        self.features.borrow().blend_minmax_enabled
+    }
+
+    pub fn is_float_buffer_renderable(&self) -> bool {
+        self.is_enabled::<WEBGLColorBufferFloat>() || self.is_enabled::<OESTextureFloat>()
+    }
+
+    pub fn is_min_glsl_version_satisfied(&self, min_glsl_version: WebGLSLVersion) -> bool {
+        self.glsl_version >= min_glsl_version
+    }
+
+    pub fn is_half_float_buffer_renderable(&self) -> bool {
+        self.is_enabled::<EXTColorBufferHalfFloat>() || self.is_enabled::<OESTextureHalfFloat>()
+    }
+
+    pub fn effective_type(&self, type_: u32) -> u32 {
+        if type_ == OESTextureHalfFloatConstants::HALF_FLOAT_OES {
+            if !self.supports_gl_extension("GL_OES_texture_half_float") {
+                return gl::HALF_FLOAT;
+            }
+        }
+        type_
+    }
+
+    pub fn is_gles(&self) -> bool {
+        self.api_type == GlType::Gles
+    }
+}
+
+// Helper structs
+#[derive(Eq, Hash, JSTraceable, MallocSizeOf, PartialEq)]
+struct TexFormatType(TexFormat, u32);
diff --git a/components/script/dom/webgl_extensions/mod.rs b/components/script/dom/webgl_extensions/mod.rs
new file mode 100644
index 00000000000..aa6dfd1c752
--- /dev/null
+++ b/components/script/dom/webgl_extensions/mod.rs
@@ -0,0 +1,12 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+pub mod ext;
+mod extension;
+mod extensions;
+mod wrapper;
+
+pub use self::extension::WebGLExtension;
+pub use self::extension::WebGLExtensionSpec;
+pub use self::extensions::WebGLExtensions;
diff --git a/components/script/dom/webgl_extensions/wrapper.rs b/components/script/dom/webgl_extensions/wrapper.rs
new file mode 100644
index 00000000000..bf8db31418c
--- /dev/null
+++ b/components/script/dom/webgl_extensions/wrapper.rs
@@ -0,0 +1,91 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::reflector::DomObject;
+use crate::dom::bindings::root::MutNullableDom;
+use crate::dom::bindings::trace::JSTraceable;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use js::jsapi::JSObject;
+use malloc_size_of::MallocSizeOf;
+use std::any::Any;
+use std::ptr::NonNull;
+
+/// Trait used internally by WebGLExtensions to store and
+/// handle the different WebGL extensions in a common list.
+pub trait WebGLExtensionWrapper: JSTraceable + MallocSizeOf {
+    fn instance_or_init(
+        &self,
+        ctx: &WebGLRenderingContext,
+        ext: &WebGLExtensions,
+    ) -> NonNull<JSObject>;
+    fn spec(&self) -> WebGLExtensionSpec;
+    fn is_supported(&self, _: &WebGLExtensions) -> bool;
+    fn is_enabled(&self) -> bool;
+    fn enable(&self, ext: &WebGLExtensions);
+    fn name(&self) -> &'static str;
+    fn as_any(&self) -> &dyn Any;
+}
+
+#[unrooted_must_root_lint::must_root]
+#[derive(JSTraceable, MallocSizeOf)]
+pub struct TypedWebGLExtensionWrapper<T: WebGLExtension> {
+    extension: MutNullableDom<T::Extension>,
+}
+
+/// Typed WebGL Extension implementation.
+/// Exposes the exact MutNullableDom<DOMObject> type defined by the extension.
+impl<T: WebGLExtension> TypedWebGLExtensionWrapper<T> {
+    pub fn new() -> TypedWebGLExtensionWrapper<T> {
+        TypedWebGLExtensionWrapper {
+            extension: MutNullableDom::new(None),
+        }
+    }
+}
+
+impl<T> WebGLExtensionWrapper for TypedWebGLExtensionWrapper<T>
+where
+    T: WebGLExtension + JSTraceable + MallocSizeOf + 'static,
+{
+    #[allow(unsafe_code)]
+    fn instance_or_init(
+        &self,
+        ctx: &WebGLRenderingContext,
+        ext: &WebGLExtensions,
+    ) -> NonNull<JSObject> {
+        let mut enabled = true;
+        let extension = self.extension.or_init(|| {
+            enabled = false;
+            T::new(ctx)
+        });
+        if !enabled {
+            self.enable(ext);
+        }
+        unsafe { NonNull::new_unchecked(extension.reflector().get_jsobject().get()) }
+    }
+
+    fn spec(&self) -> WebGLExtensionSpec {
+        T::spec()
+    }
+
+    fn is_supported(&self, ext: &WebGLExtensions) -> bool {
+        self.is_enabled() || T::is_supported(ext)
+    }
+
+    fn is_enabled(&self) -> bool {
+        self.extension.get().is_some()
+    }
+
+    fn enable(&self, ext: &WebGLExtensions) {
+        T::enable(ext);
+    }
+
+    fn name(&self) -> &'static str {
+        T::name()
+    }
+
+    fn as_any<'a>(&'a self) -> &'a dyn Any {
+        self
+    }
+}