Define a --force-gpu-rasterization flag

cc/layers/picture_layer_impl.cc

 // Copyright 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/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/time/time.h"
@@ skipping 36 matching lines @@
       ideal_contents_scale_(0.f),
       raster_page_scale_(0.f),
       raster_device_scale_(0.f),
       raster_source_scale_(0.f),
       raster_contents_scale_(0.f),
       low_res_raster_contents_scale_(0.f),
       raster_source_scale_was_animating_(false),
       is_using_lcd_text_(tree_impl->settings().can_use_lcd_text),
       needs_post_commit_initialization_(true),
       should_update_tile_priorities_(false),
-      should_use_gpu_rasterization_(tree_impl->settings().gpu_rasterization) {}
+      should_use_gpu_rasterization_(
+          tree_impl->settings().gpu_rasterization_state ==
+          LayerTreeSettings::GpuRasterizationForced) {}
 
 PictureLayerImpl::~PictureLayerImpl() {}
 
 const char* PictureLayerImpl::LayerTypeAsString() const {
   return "cc::PictureLayerImpl";
 }
 
 scoped_ptr<LayerImpl> PictureLayerImpl::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
   return PictureLayerImpl::Create(tree_impl, id()).PassAs<LayerImpl>();
@@ skipping 1170 matching lines @@
 size_t PictureLayerImpl::GPUMemoryUsageInBytes() const {
   const_cast<PictureLayerImpl*>(this)->DoPostCommitInitializationIfNeeded();
   return tilings_->GPUMemoryUsageInBytes();
 }
 
 void PictureLayerImpl::RunMicroBenchmark(MicroBenchmarkImpl* benchmark) {
   benchmark->RunOnLayer(this);
 }
 
 }  // namespace cc