mac: Use IOSurfaces in Canvas2DLayerBridge.

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 "build/build_config.h"
 #include "content/public/common/content_switches.h"
 
 namespace switches {
 
 // The number of MSAA samples for canvas2D. Requires MSAA support by GPU to
@@ skipping 55 matching lines @@
 // Dumps extra logging about plugin loading to the log file.
 const char kDebugPluginLoading[] = "debug-plugin-loading";
 
 // Sets the tile size used by composited layers.
 const char kDefaultTileWidth[]              = "default-tile-width";
 const char kDefaultTileHeight[]             = "default-tile-height";
 
 // Disable antialiasing on 2d canvas.
 const char kDisable2dCanvasAntialiasing[]   = "disable-canvas-aa";
 
+// Disables Canvas2D rendering into a scanout buffer for overlay support.
+const char kDisable2dCanvasImageChromium[] = "disable-2d-canvas-image-chromium";
+
 // Disables client-visible 3D APIs, in particular WebGL and Pepper 3D.
 // This is controlled by policy and is kept separate from the other
 // enable/disable switches to avoid accidentally regressing the policy
 // support for controlling access to these APIs.
 const char kDisable3DAPIs[]                 = "disable-3d-apis";
 
 // Disable gpu-accelerated 2d canvas.
 const char kDisableAccelerated2dCanvas[]    = "disable-accelerated-2d-canvas";
 
 // Disable hardware acceleration of mjpeg decode for captured frame, where
@@ skipping 952 matching lines @@
 const char kMemoryPressureThresholdsMb[] = "memory-pressure-thresholds-mb";
 
 // Enables the exporting of the tracing events to ETW. This is only supported on
 // Windows Vista and later.
 const char kTraceExportEventsToETW[] = "trace-export-events-to-etw";
 #endif
 
 // Don't dump stuff here, follow the same order as the header.
 
 }  // namespace switches