Add GPU memory tab to the task manager.

content/browser/gpu/gpu_process_host_ui_shim.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_GPU_GPU_PROCESS_HOST_UI_SHIM_H_
 #define CONTENT_BROWSER_GPU_GPU_PROCESS_HOST_UI_SHIM_H_
 
 // This class lives on the UI thread and supports classes like the
 // BackingStoreProxy, which must live on the UI thread. The IO thread
 // portion of this class, the GpuProcessHost, is responsible for
@@ skipping 82 matching lines @@
 
   void OnAcceleratedSurfaceBuffersSwapped(
       const GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params& params);
   void OnAcceleratedSurfacePostSubBuffer(
       const GpuHostMsg_AcceleratedSurfacePostSubBuffer_Params& params);
   void OnAcceleratedSurfaceSuspend(int32 surface_id);
   void OnAcceleratedSurfaceNew(
       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_;
 };
 
 #endif  // CONTENT_BROWSER_GPU_GPU_PROCESS_HOST_UI_SHIM_H_