cc: Trigger GPU rasterization based on a per-layer hint

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #if defined(OS_ANDROID)
@@ skipping 109 matching lines @@
   if (cmd->HasSwitch(switches::kMaxUntiledLayerHeight)) {
     GetSwitchValueAsInt(*cmd, switches::kMaxUntiledLayerHeight, 1,
                         std::numeric_limits<int>::max(),
                         &max_untiled_layer_height);
   }
 
   settings.max_untiled_layer_size = gfx::Size(max_untiled_layer_width,
                                            max_untiled_layer_height);
 
   settings.impl_side_painting = cc::switches::IsImplSidePaintingEnabled();
-  settings.gpu_rasterization = cc::switches::IsGpuRasterizationEnabled();
+  if (cc::switches::IsGpuRasterizationEnabled())

[Vangelis Kokkevis, 2014/03/05 19:52:08]

Should we also check if impl-side-painting is enabled and if not revert to
CpuRasterization, to avoid confusion from incompatible flags? 

[ajuma, 2014/03/05 20:37:03]

Good idea. I've added this check to IsGpuRasterizationEnabled and to
IsHybridRasterizationEnabled.

+    settings.rasterization_site = cc::LayerTreeSettings::GpuRasterization;
+  else if (cc::switches::IsHybridRasterizationEnabled())
+    settings.rasterization_site = cc::LayerTreeSettings::HybridRasterization;
+  else
+    settings.rasterization_site = cc::LayerTreeSettings::CpuRasterization;
 
   settings.calculate_top_controls_position =
       cmd->HasSwitch(cc::switches::kEnableTopControlsPositionCalculation);
   if (cmd->HasSwitch(cc::switches::kTopControlsHeight)) {
     std::string controls_height_str =
         cmd->GetSwitchValueASCII(cc::switches::kTopControlsHeight);
     double controls_height;
     if (base::StringToDouble(controls_height_str, &controls_height) &&
         controls_height > 0)
       settings.top_controls_height = controls_height;
@@ skipping 491 matching lines @@
   widget_->OnSwapBuffersAborted();
 }
 
 void RenderWidgetCompositor::RateLimitSharedMainThreadContext() {
   cc::ContextProvider* provider =
       RenderThreadImpl::current()->SharedMainThreadContextProvider().get();
   provider->ContextGL()->RateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content