Add GPU memory tab to the task manager.

content/browser/gpu/gpu_process_host_ui_shim.h

Index: content/browser/gpu/gpu_process_host_ui_shim.h
diff --git a/content/browser/gpu/gpu_process_host_ui_shim.h b/content/browser/gpu/gpu_process_host_ui_shim.h
index 5f3f4c85c22508248a7898b0e0e5676042eda15d..dd653a2070792e71dc2aa6755ae938e0e071711a 100644
--- a/content/browser/gpu/gpu_process_host_ui_shim.h
+++ b/content/browser/gpu/gpu_process_host_ui_shim.h
@@ -100,6 +100,8 @@ class GpuProcessHostUIShim
       const GpuHostMsg_AcceleratedSurfaceNew_Params& params);
   void OnAcceleratedSurfaceRelease(
       const GpuHostMsg_AcceleratedSurfaceRelease_Params& params);
+  void OnVidmemUsageStats(

[greggman, 2012/08/16 00:24:15]

I still have no idea what this does without looking at the implementation where
as I know what all other messages do

OnAcceleratedSurfaceBuffersSwapped clearly gets called whtn the surface buffers
are swapped.

OnAccleratedSurfaceNew clearly gets called when a new surface is created

OnVidmemUsageStats gets called when? When they're updated? When they're created?
When they're deleted? 

[ccameron, 2012/08/16 00:38:53]

Yeah, still true.  I've updated it to OnVidmemUsageStatsReceived (so it happens
when you receive a a new set of vidmem usage statistics via
GpuHostMsg_VidmemUsageStats from the GPU process).

+      const content::GPUVidmemUsageStats& vidmem_usage_stats);
 
   // The serial number of the GpuProcessHost / GpuProcessHostUIShim pair.
   int host_id_;