Add flag for drawing layers to screen with Ganesh

cc/base/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 "cc/base/switches.h"
 
 #include "base/command_line.h"
 
 namespace cc {
 namespace switches {
@@ skipping 20 matching lines @@
 
 // Try to finish display pipeline before vsync tick
 const char kEnableRightAlignedScheduling[] = "enable-right-aligned-scheduling";
 
 const char kEnableTopControlsPositionCalculation[] =
     "enable-top-controls-position-calculation";
 
 // Enable solid tile color and transparent tile metrics.
 const char kEnablePredictionBenchmarking[] = "enable-prediction-benchmarking";
 
+// For any layers that can get drawn directly to screen, draw them with Ganesh.
+// Only valid with gl rendering + threaded compositing + impl-side painting.
+const char kForceDirectLayerDrawing[] = "force-direct-layer-drawing";
+
 // The height of the movable top controls.
 const char kTopControlsHeight[] = "top-controls-height";
 
 // Percentage of the top controls need to be hidden before they will auto hide.
 const char kTopControlsHideThreshold[] = "top-controls-hide-threshold";
 
 // Percentage of the top controls need to be shown before they will auto show.
 const char kTopControlsShowThreshold[] = "top-controls-show-threshold";
 
 // Number of worker threads used to rasterize content.
@@ skipping 108 matching lines @@
   return false;
 #elif defined(OS_ANDROID)
   return true;
 #else
   return false;
 #endif
 }
 
 }  // namespace switches
 }  // namespace cc