Revert "Auto merge of #17891 - MortimerGoro:webgl_move, r=glennw,emilio"

This reverts commit 90f55ea4580e2a15f7d70d0491444f18b972d450, reversing
changes made to 2e60b27a2186a8cba4b952960155dfcf3f47d7db.

1 files changed, 35 insertions, 31 deletions

diff --git a/components/script/dom/htmlcanvaselement.rs b/components/script/dom/htmlcanvaselement.rs
index 3d89c08b230..a95ff766171 100644
--- a/components/script/dom/htmlcanvaselement.rs
+++ b/components/script/dom/htmlcanvaselement.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use base64;
-use canvas_traits::canvas::{CanvasMsg, FromScriptMsg};
+use canvas_traits::{CanvasMsg, FromScriptMsg};
 use dom::attr::Attr;
 use dom::bindings::cell::DOMRefCell;
 use dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding::CanvasRenderingContext2DMethods;
@@ -30,11 +30,11 @@ use euclid::Size2D;
 use html5ever::{LocalName, Prefix};
 use image::ColorType;
 use image::png::PNGEncoder;
-use ipc_channel::ipc;
+use ipc_channel::ipc::{self, IpcSender};
 use js::error::throw_type_error;
 use js::jsapi::{HandleValue, JSContext};
 use offscreen_gl_context::GLContextAttributes;
-use script_layout_interface::{HTMLCanvasData, HTMLCanvasDataSource};
+use script_layout_interface::HTMLCanvasData;
 use std::iter::repeat;
 use style::attr::{AttrValue, LengthOrPercentageOrAuto};
 
@@ -106,22 +106,21 @@ impl LayoutHTMLCanvasElementHelpers for LayoutJS<HTMLCanvasElement> {
     fn data(&self) -> HTMLCanvasData {
         unsafe {
             let canvas = &*self.unsafe_get();
-            let source = match canvas.context.borrow_for_layout().as_ref() {
-                Some(&CanvasContext::Context2d(ref context)) => {
-                    HTMLCanvasDataSource::Image(Some(context.to_layout().get_ipc_renderer()))
-                },
-                Some(&CanvasContext::WebGL(ref context)) => {
-                    context.to_layout().canvas_data_source()
-                },
-                None => {
-                    HTMLCanvasDataSource::Image(None)
+            let ipc_renderer = canvas.context.borrow_for_layout().as_ref().map(|context| {
+                match *context {
+                    CanvasContext::Context2d(ref context) => {
+                        context.to_layout().get_ipc_renderer()
+                    },
+                    CanvasContext::WebGL(ref context) => {
+                        context.to_layout().get_ipc_renderer()
+                    },
                 }
-            };
+            });
 
             let width_attr = canvas.upcast::<Element>().get_attr_for_layout(&ns!(), &local_name!("width"));
             let height_attr = canvas.upcast::<Element>().get_attr_for_layout(&ns!(), &local_name!("height"));
             HTMLCanvasData {
-                source: source,
+                ipc_renderer: ipc_renderer,
                 width: width_attr.map_or(DEFAULT_WIDTH, |val| val.as_uint()),
                 height: height_attr.map_or(DEFAULT_HEIGHT, |val| val.as_uint()),
             }
@@ -151,6 +150,15 @@ impl LayoutHTMLCanvasElementHelpers for LayoutJS<HTMLCanvasElement> {
 
 
 impl HTMLCanvasElement {
+    pub fn ipc_renderer(&self) -> Option<IpcSender<CanvasMsg>> {
+        self.context.borrow().as_ref().map(|context| {
+            match *context {
+                CanvasContext::Context2d(ref context) => context.ipc_renderer(),
+                CanvasContext::WebGL(ref context) => context.ipc_renderer(),
+            }
+        })
+    }
+
     pub fn get_or_init_2d_context(&self) -> Option<Root<CanvasRenderingContext2D>> {
         if self.context.borrow().is_none() {
             let window = window_from_node(self);
@@ -213,26 +221,22 @@ impl HTMLCanvasElement {
             return None
         }
 
-        let data = match self.context.borrow().as_ref() {
-            Some(&CanvasContext::Context2d(ref context)) => {
-                let (sender, receiver) = ipc::channel().unwrap();
-                let msg = CanvasMsg::FromScript(FromScriptMsg::SendPixels(sender));
-                context.get_ipc_renderer().send(msg).unwrap();
+        let data = if let Some(renderer) = self.ipc_renderer() {
+            let (sender, receiver) = ipc::channel().unwrap();
+            let msg = CanvasMsg::FromScript(FromScriptMsg::SendPixels(sender));
+            renderer.send(msg).unwrap();
 
-                match receiver.recv().unwrap() {
-                    Some(pixels) => pixels,
-                    None => {
-                        return None;
-                    }
+            match receiver.recv().unwrap() {
+                Some(pixels) => pixels,
+                None => {
+                    // TODO(emilio, #14109): Not sure if WebGL canvas is
+                    // required for 2d spec, but I think it's not, if so, make
+                    // this return a readback from the GL context.
+                    return None;
                 }
-            },
-            Some(&CanvasContext::WebGL(_)) => {
-                // TODO: add a method in WebGLRenderingContext to get the pixels.
-                return None;
-            },
-            None => {
-                repeat(0xffu8).take((size.height as usize) * (size.width as usize) * 4).collect()
             }
+        } else {
+            repeat(0xffu8).take((size.height as usize) * (size.width as usize) * 4).collect()
         };
 
         Some((data, size))