Add gpu_memory_usage to Tile::AsValue

Will let us show gpu memory usage in a more-intuitive way in frame viewer.

Review URL: https://codereview.chromium.org/447963004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@287998 0039d316-1c4b-4281-b951-d872f2087c98

cc/resources/tile.cc

@@ -87,6 +87,8 @@ void Tile::AsValueInto(base::debug::TracedValue* res) const {
   res->EndDictionary();
 
   res->SetBoolean("use_picture_analysis", use_picture_analysis());
+
+  res->SetInteger("gpu_memory_usage", GPUMemoryUsageInBytes());
 }
 
 size_t Tile::GPUMemoryUsageInBytes() const {