Wire up the JS engine's memory reporting.

SpiderMonkey provides an extremely fine-grained breakdown of memory
usage, but for Servo we aggregate the measurements into a small number
of coarse buckets, which seems appropriate for the current level of
detail provided by Servo's memory profiler. Sample output:
```
|   10.99 MiB -- pages
|       7.75 MiB -- url(http://html5demos.com/worker)
|          4.63 MiB -- js
|             2.00 MiB -- gc-heap
|                0.94 MiB -- decommitted
|                0.92 MiB -- used
|                0.09 MiB -- unused
|                0.05 MiB -- admin
|             1.44 MiB -- malloc-heap
|             1.19 MiB -- non-heap
|          [...]
|       3.24 MiB -- url(http://html5demos.com/js/worker-cruncher.js)
|          3.24 MiB -- js
|             1.17 MiB -- malloc-heap
|             1.06 MiB -- non-heap
|             1.00 MiB -- gc-heap
|                0.69 MiB -- used
|                0.19 MiB -- decommitted
|                0.09 MiB -- unused
|                0.03 MiB -- admin
```
Most of the changes are plumbing to get the script and worker tasks
communicating with the memory profiler task.

1 files changed, 2 insertions, 0 deletions

diff --git a/components/script/dom/bindings/trace.rs b/components/script/dom/bindings/trace.rs
index b03255cd986..5ed5ed0bb52 100644
--- a/components/script/dom/bindings/trace.rs
+++ b/components/script/dom/bindings/trace.rs
@@ -60,6 +60,7 @@ use smallvec::SmallVec1;
 use msg::compositor_msg::ScriptListener;
 use msg::constellation_msg::ConstellationChan;
 use net_traits::image::base::Image;
+use profile_traits::mem::ProfilerChan;
 use util::str::{LengthOrPercentageOrAuto};
 use std::cell::{Cell, UnsafeCell, RefCell};
 use std::collections::{HashMap, HashSet};
@@ -299,6 +300,7 @@ no_jsmanaged_fields!(CanvasGradientStop, LinearGradientStyle, RadialGradientStyl
 no_jsmanaged_fields!(LineCapStyle, LineJoinStyle, CompositionOrBlending);
 no_jsmanaged_fields!(RepetitionStyle);
 no_jsmanaged_fields!(WebGLError);
+no_jsmanaged_fields!(ProfilerChan);
 
 impl JSTraceable for Box<ScriptChan+Send> {
     #[inline]