cc: Re-enable GPU rasterization after content veto.

cc/trees/layer_tree_host.cc

 // Copyright 2011 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/trees/layer_tree_host.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1032 matching lines @@
     draw_property_utils::FindLayersThatNeedUpdates(
         this, property_trees_.transform_tree, property_trees_.effect_tree,
         &update_layer_list);
   }
 
   for (const auto& layer : update_layer_list)
     layer->SavePaintProperties();
 
   base::AutoReset<bool> painting(&in_paint_layer_contents_, true);
   bool did_paint_content = false;
+  bool content_is_suitable_for_gpu = true;
   for (const auto& layer : update_layer_list) {
     did_paint_content |= layer->Update();
-    content_is_suitable_for_gpu_rasterization_ &=
-        layer->IsSuitableForGpuRasterization();
+    content_is_suitable_for_gpu &= layer->IsSuitableForGpuRasterization();
+  }
+
+  if (content_is_suitable_for_gpu) {
+    ++num_consecutive_frames_suitable_for_gpu_;
+    if (num_consecutive_frames_suitable_for_gpu_ >=
+        kNumFramesToConsiderBeforeGpuRasterization) {
+      content_is_suitable_for_gpu_rasterization_ = true;
+    }
+  } else {
+    num_consecutive_frames_suitable_for_gpu_ = 0;
+    content_is_suitable_for_gpu_rasterization_ = false;
   }
   return did_paint_content;
 }
 
 void LayerTreeHost::ApplyScrollAndScale(ScrollAndScaleSet* info) {
   for (auto& swap_promise : info->swap_promises) {
     TRACE_EVENT_WITH_FLOW1("input,benchmark",
                            "LatencyInfo.Flow",
                            TRACE_ID_DONT_MANGLE(swap_promise->TraceId()),
                            TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT,
@@ skipping 695 matching lines @@
   int seq_num = property_trees_.sequence_number;
   LayerTreeHostCommon::CallFunctionForEveryLayer(this, [seq_num](Layer* layer) {
     layer->set_property_tree_sequence_number(seq_num);
   });
 
   surface_id_namespace_ = proto.surface_id_namespace();
   next_surface_sequence_ = proto.next_surface_sequence();
 }
 
 }  // namespace cc