Introduce GlobalScope::constellation_chan

components/script/dom/globalscope.rs

@@ -12,6 +12,7 @@ use dom::eventtarget::EventTarget;
 use ipc_channel::ipc::IpcSender;
 use js::jsapi::{JS_GetContext, JS_GetObjectRuntime, JSContext};
 use profile_traits::{mem, time};
+use script_traits::ScriptMsg as ConstellationMsg;
 use std::cell::Cell;
 use std::collections::HashMap;
 use std::collections::hash_map::Entry;
@@ -41,13 +42,18 @@ pub struct GlobalScope {
     /// For sending messages to the time profiler.
     #[ignore_heap_size_of = "channels are hard"]
     time_profiler_chan: time::ProfilerChan,
+
+    /// A handle for communicating messages to the constellation thread.
+    #[ignore_heap_size_of = "channels are hard"]
+    constellation_chan: IpcSender<ConstellationMsg>,
 }
 
 impl GlobalScope {
     pub fn new_inherited(
             devtools_chan: Option<IpcSender<ScriptToDevtoolsControlMsg>>,
             mem_profiler_chan: mem::ProfilerChan,
-            time_profiler_chan: time::ProfilerChan)
+            time_profiler_chan: time::ProfilerChan,
+            constellation_chan: IpcSender<ConstellationMsg>)
             -> Self {
         GlobalScope {
             eventtarget: EventTarget::new_inherited(),
@@ -58,6 +64,7 @@ impl GlobalScope {
             devtools_chan: devtools_chan,
             mem_profiler_chan: mem_profiler_chan,
             time_profiler_chan: time_profiler_chan,
+            constellation_chan: constellation_chan,
         }
     }
 
@@ -128,6 +135,11 @@ impl GlobalScope {
     pub fn time_profiler_chan(&self) -> &time::ProfilerChan {
         &self.time_profiler_chan
     }
+
+    /// Get a sender to the constellation thread.
+    pub fn constellation_chan(&self) -> &IpcSender<ConstellationMsg> {
+        &self.constellation_chan
+    }
 }
 
 fn timestamp_in_ms(time: Timespec) -> u64 {