2 files changed, 28 insertions, 8 deletions
diff --git a/src/components/msg/compositor.rs b/src/components/msg/compositor.rs
index 6b6311fd1ba..6d8fe2ecc50 100644
--- a/src/components/msg/compositor.rs
+++ b/src/components/msg/compositor.rs
@@ -6,6 +6,7 @@ use azure::azure_hl::DrawTarget;
 use azure::azure::AzGLContext;
 use geom::rect::Rect;
 use geom::size::Size2D;
+use std::util::NonCopyable;
 
 pub struct LayerBuffer {
     draw_target: DrawTarget,
@@ -33,14 +34,6 @@ pub enum RenderState {
     RenderingRenderState,
 }
 
-/// The interface used by the renderer to acquire draw targets for each rendered frame and
-/// submit them to be drawn to the display.
-pub trait RenderListener {
-    fn get_gl_context(&self) -> AzGLContext;
-    fn paint(&self, layer_buffer_set: LayerBufferSet, new_size: Size2D<uint>);
-    fn set_render_state(&self, render_state: RenderState);
-}
-
 pub enum ReadyState {
     /// Informs the compositor that a page is loading. Used for setting status
     Loading,
@@ -50,8 +43,30 @@ pub enum ReadyState {
     FinishedLoading,
 }
 
+/// The interface used by the renderer to acquire draw targets for each render frame and
+/// submit them to be drawn to the display.
+pub trait RenderListener {
+    fn get_gl_context(&self) -> AzGLContext;
+    fn paint(&self, layer_buffer_set: LayerBufferSet, new_size: Size2D<uint>);
+    fn set_render_state(&self, render_state: RenderState);
+}
+
 /// The interface used by the script task to tell the compositor to update its ready state,
 /// which is used in displaying the appropriate message in the window's title.
 pub trait ScriptListener : Clone {
     fn set_ready_state(&self, ReadyState);
 }
+
+/// Signifies control of the compositor. Only the render task controlling
+/// the compositor token may send paint messages to the compositor
+pub struct CompositorToken {
+    construction_restrictor: NonCopyable,
+}
+
+impl CompositorToken {
+    pub fn new() -> CompositorToken {
+        CompositorToken {
+            construction_restrictor: NonCopyable::new(),
+        }
+    }
+}
diff --git a/src/components/msg/engine.rs b/src/components/msg/engine.rs
index 83e0f085ee0..b03893d14ca 100644
--- a/src/components/msg/engine.rs
+++ b/src/components/msg/engine.rs
@@ -7,6 +7,9 @@
 
 use std::comm::{Chan, SharedChan};
 use extra::net::url::Url;
+use compositor::CompositorToken;
+
+pub use compositor;
 
 #[deriving(Clone)]
 pub struct EngineChan {
@@ -27,5 +30,7 @@ impl EngineChan {
 pub enum Msg {
     LoadUrlMsg(Url),
     ExitMsg(Chan<()>),
+    RendererReadyMsg(uint),
+    TokenSurrenderMsg(~CompositorToken),
 }