cc: Add UMA to measure the raster duration for pending tree activation.

cc/trees/layer_tree_host_impl.h

 // 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.
 
 #ifndef CC_TREES_LAYER_TREE_HOST_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <stddef.h>
 
 #include <bitset>
@@ skipping 48 matching lines @@
 class DebugRectHistory;
 class EvictionTilePriorityQueue;
 class FrameRateCounter;
 class LayerImpl;
 class LayerTreeImpl;
 class MemoryHistory;
 class MutatorEvents;
 class MutatorHost;
 class PageScaleAnimation;
 class PendingTreeDurationHistogramTimer;
+class PendingTreeRasterDurationHistogramTimer;
 class RasterTilePriorityQueue;
 class RasterBufferProvider;
 class RenderingStatsInstrumentation;
 class ResourcePool;
 class ScrollElasticityHelper;
 class SwapPromise;
 class SwapPromiseMonitor;
 class SynchronousTaskGraphRunner;
 class TaskGraphRunner;
 class UIResourceBitmap;
@@ skipping 775 matching lines @@
   // TODO(danakj): Delete the LayerTreeFrameSink and all resources when
   // it's lost instead of having this bool.
   bool has_valid_layer_tree_frame_sink_;
 
   std::unique_ptr<Viewport> viewport_;
 
   std::unique_ptr<LayerTreeMutator> mutator_;
 
   std::unique_ptr<PendingTreeDurationHistogramTimer>
       pending_tree_duration_timer_;
+  std::unique_ptr<PendingTreeRasterDurationHistogramTimer>
+      pending_tree_raster_duration_timer_;
 
   // The id of the scroll node to which scroll animations must latch.
   // This gets reset at ScrollAnimatedBegin, and updated the first time that a
   // scroll animation is created in ScrollAnimated.
   int scroll_animating_latched_node_id_;
 
   // These callbacks are stored here to be transfered to the main thread when we
   // begin main frame. These callbacks must only be called on the main thread.
   std::vector<base::Closure> completed_image_decode_callbacks_;
 
   // These are used to transfer usage of touch and wheel scrolls to the main
   // thread.
   bool has_scrolled_by_wheel_;
   bool has_scrolled_by_touch_;
 
   bool touchpad_and_wheel_scroll_latching_enabled_;
 
   ImplThreadPhase impl_thread_phase_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_