Add a command-line flag to enable threaded GPU rasterization.

content/public/common/content_switches.cc

 // 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.
 
 #include "content/public/common/content_switches.h"
 
 namespace switches {
 
 // The number of MSAA samples for canvas2D. Requires MSAA support by GPU to
 // have an effect. 0 disables MSAA.
@@ skipping 480 matching lines @@
 // Always use the Skia GPU backend for drawing layer tiles. Only valid with GPU
 // accelerated compositing + impl-side painting. Overrides the
 // kEnableGpuRasterization flag.
 const char kForceGpuRasterization[]        = "force-gpu-rasterization";
 
 // The number of multisample antialiasing samples for GPU rasterization.
 // Requires MSAA support on GPU to have an effect. 0 disables MSAA.
 const char kGpuRasterizationMSAASampleCount[] =
     "gpu-rasterization-msaa-sample-count";
 
+// Enable threaded GPU rasterization.
+const char kEnableThreadedGpuRasterization[] =
+    "enable-threaded-gpu-rasterization";
+
+// Disable threaded GPU rasterization.  Overrides enable.
+const char kDisableThreadedGpuRasterization[] =
+    "disable-threaded-gpu-rasterization";
+
 // Force renderer accessibility to be on instead of enabling it on demand when
 // a screen reader is detected. The disable-renderer-accessibility switch
 // overrides this if present.
 const char kForceRendererAccessibility[]    = "force-renderer-accessibility";
 
 // Always use text blob rendering, overriding kDisableTextBlobs and any
 // heuristics that may otherwise disable it.
 // TODO(fmalita): remove after --disable-impl-side-painting is phased out.
 const char kForceTextBlobs[]                = "force-text-blobs";
 
@@ skipping 448 matching lines @@
 const char kEnableNpapi[]                   = "enable-npapi";
 
 #if defined(ENABLE_PLUGINS)
 // Enables the plugin power saver feature.
 const char kEnablePluginPowerSaver[] = "enable-plugin-power-saver";
 #endif
 
 // Don't dump stuff here, follow the same order as the header.
 
 }  // namespace switches