Add category handling to RasterWorkerPool

content/public/common/content_switches.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.
 
 // Defines all the "content" command-line switches.
 
 #ifndef CONTENT_PUBLIC_COMMON_CONTENT_SWITCHES_H_
 #define CONTENT_PUBLIC_COMMON_CONTENT_SWITCHES_H_
 
 #include "build/build_config.h"
@@ skipping 214 matching lines @@
 CONTENT_EXPORT extern const char kTouchTextSelectionStrategy[];
 CONTENT_EXPORT extern const char kUIPrioritizeInGpuProcess[];
 CONTENT_EXPORT extern const char kUseFakeUIForMediaStream[];
 CONTENT_EXPORT extern const char kUseMusInRenderer[];
 CONTENT_EXPORT extern const char kEnableNativeGpuMemoryBuffers[];
 CONTENT_EXPORT extern const char kContentImageTextureTarget[];
 CONTENT_EXPORT extern const char kVideoImageTextureTarget[];
 CONTENT_EXPORT extern const char kUseMobileUserAgent[];
 CONTENT_EXPORT extern const char kUseNormalPriorityForTileTaskWorkerThreads[];
 CONTENT_EXPORT extern const char kUseRemoteCompositing[];
+CONTENT_EXPORT extern const char kUseSingleThreadForBackgroundRasterTasks[];

[reveman, 2016/01/13 23:09:30]

nit: Remove "Raster" as this technically not limited to raster tasks.

However, I don't think we need a flag for this. Even if we haven't been able to
demonstrate a huge benefit yet I think it makes sense to always use this. I'm
expecting the benefit to come from increasing the number of raster threads
without the regression in responsiveness that we've seen in the past.

[ericrk, 2016/01/21 01:19:44]

Fair enough - we can see what happens when we land this without the flag.

 extern const char kUseSurfaces[];
 CONTENT_EXPORT extern const char kDisableSurfaces[];
 extern const char kUtilityCmdPrefix[];
 CONTENT_EXPORT extern const char kUtilityProcess[];
 extern const char kUtilityProcessAllowedDir[];
 CONTENT_EXPORT extern const char kUtilityProcessRunningElevated[];
 CONTENT_EXPORT extern const char kV8CacheOptions[];
 CONTENT_EXPORT extern const char kV8NativesPassedByFD[];
 CONTENT_EXPORT extern const char kV8SnapshotPassedByFD[];
 CONTENT_EXPORT extern const char kValidateInputEventStream[];
@@ skipping 57 matching lines @@
 CONTENT_EXPORT extern const char kMemoryPressureThresholdsMb[];
 CONTENT_EXPORT extern const char kTraceExportEventsToETW[];
 #endif
 
 // DON'T ADD RANDOM STUFF HERE. Put it in the main section above in
 // alphabetical order, or in one of the ifdefs (also in order in each section).
 
 }  // namespace switches
 
 #endif  // CONTENT_PUBLIC_COMMON_CONTENT_SWITCHES_H_