Auto merge of #11265 - Ms2ger:cleanup, r=nox

Some assorted cleanup.

Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data:
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy --faster` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

Either:
- [ ] There are tests for these changes OR
- [x] These changes do not require tests because _____

Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process.

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components/canvas/canvas_paint_thread.rs

@@ -117,13 +117,11 @@ impl<'a> CanvasPaintThread<'a> {
         }
     }
 
-    /// Creates a new `CanvasPaintThread` and returns the out-of-process sender and the in-process
-    /// sender for it.
+    /// Creates a new `CanvasPaintThread` and returns an `IpcSender` to
+    /// communicate with it.
     pub fn start(size: Size2D<i32>,
                  webrender_api_sender: Option<webrender_traits::RenderApiSender>)
                  -> IpcSender<CanvasMsg> {
-        // TODO(pcwalton): Ask the pipeline to create this for us instead of spawning it directly.
-        // This will be needed for multiprocess Servo.
         let (sender, receiver) = ipc::channel::<CanvasMsg>().unwrap();
         spawn_named("CanvasThread".to_owned(), move || {
             let mut painter = CanvasPaintThread::new(size, webrender_api_sender);

components/canvas/webgl_paint_thread.rs

@@ -58,8 +58,8 @@ impl WebGLPaintThread {
         }
     }
 
-    /// Creates a new `WebGLPaintThread` and returns the out-of-process sender and the in-process
-    /// sender for it.
+    /// Creates a new `WebGLPaintThread` and returns an `IpcSender` to
+    /// communicate with it.
     pub fn start(size: Size2D<i32>,
                  attrs: GLContextAttributes,
                  webrender_api_sender: Option<webrender_traits::RenderApiSender>)

components/constellation/constellation.rs

@@ -91,38 +91,38 @@ enum ReadyToSave {
 /// the `script` crate).
 pub struct Constellation<LTF, STF> {
     /// A channel through which script messages can be sent to this object.
-    pub script_sender: ConstellationChan<FromScriptMsg>,
+    script_sender: ConstellationChan<FromScriptMsg>,
 
     /// A channel through which compositor messages can be sent to this object.
-    pub compositor_sender: Sender<FromCompositorMsg>,
+    compositor_sender: Sender<FromCompositorMsg>,
 
     /// A channel through which layout thread messages can be sent to this object.
-    pub layout_sender: ConstellationChan<FromLayoutMsg>,
+    layout_sender: ConstellationChan<FromLayoutMsg>,
 
     /// A channel through which panic messages can be sent to this object.
-    pub panic_sender: ConstellationChan<PanicMsg>,
+    panic_sender: ConstellationChan<PanicMsg>,
 
     /// Receives messages from scripts.
-    pub script_receiver: Receiver<FromScriptMsg>,
+    script_receiver: Receiver<FromScriptMsg>,
 
     /// Receives messages from the compositor
-    pub compositor_receiver: Receiver<FromCompositorMsg>,
+    compositor_receiver: Receiver<FromCompositorMsg>,
 
     /// Receives messages from the layout thread
-    pub layout_receiver: Receiver<FromLayoutMsg>,
+    layout_receiver: Receiver<FromLayoutMsg>,
 
     /// Receives panic messages.
-    pub panic_receiver: Receiver<PanicMsg>,
+    panic_receiver: Receiver<PanicMsg>,
 
     /// A channel (the implementation of which is port-specific) through which messages can be sent
     /// to the compositor.
-    pub compositor_proxy: Box<CompositorProxy>,
+    compositor_proxy: Box<CompositorProxy>,
 
     /// A channel through which messages can be sent to the resource thread.
-    pub resource_thread: ResourceThread,
+    resource_thread: ResourceThread,
 
     /// A channel through which messages can be sent to the image cache thread.
-    pub image_cache_thread: ImageCacheThread,
+    image_cache_thread: ImageCacheThread,
 
     /// A channel through which messages can be sent to the developer tools.
     devtools_chan: Option<Sender<DevtoolsControlMsg>>,
@@ -164,10 +164,10 @@ pub struct Constellation<LTF, STF> {
     pending_frames: Vec<FrameChange>,
 
     /// A channel through which messages can be sent to the time profiler.
-    pub time_profiler_chan: time::ProfilerChan,
+    time_profiler_chan: time::ProfilerChan,
 
     /// A channel through which messages can be sent to the memory profiler.
-    pub mem_profiler_chan: mem::ProfilerChan,
+    mem_profiler_chan: mem::ProfilerChan,
 
     phantom: PhantomData<(LTF, STF)>,