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

cc/trees/layer_tree_host_impl.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_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 143 matching lines @@
   } else {
     UMA_HISTOGRAM_BOOLEAN("Renderer4.CompositorTouchScrollUpdateThread",
                           scroll_on_main_thread);
   }
 }
 
 }  // namespace
 
 DEFINE_SCOPED_UMA_HISTOGRAM_TIMER(PendingTreeDurationHistogramTimer,
                                   "Scheduling.%s.PendingTreeDuration");
+DEFINE_SCOPED_UMA_HISTOGRAM_TIMER(PendingTreeRasterDurationHistogramTimer,
+                                  "Scheduling.%s.PendingTreeRasterDuration");
 
 LayerTreeHostImpl::FrameData::FrameData()
     : render_surface_list(nullptr),
       has_no_damage(false),
       may_contain_video(false) {}
 
 LayerTreeHostImpl::FrameData::~FrameData() {}
 
 std::unique_ptr<LayerTreeHostImpl> LayerTreeHostImpl::Create(
     const LayerTreeSettings& settings,
@@ skipping 206 matching lines @@
   bool did_prepare_tiles = PrepareTiles();
   if (!did_prepare_tiles) {
     NotifyReadyToActivate();
 
     // Ensure we get ReadyToDraw signal even when PrepareTiles not run. This
     // is important for SingleThreadProxy and impl-side painting case. For
     // STP, we commit to active tree and RequiresHighResToDraw, and set
     // Scheduler to wait for ReadyToDraw signal to avoid Checkerboard.
     if (CommitToActiveTree())
       NotifyReadyToDraw();
+  } else if (!CommitToActiveTree()) {
+    DCHECK(!pending_tree_raster_duration_timer_);
+    pending_tree_raster_duration_timer_ =
+        base::MakeUnique<PendingTreeRasterDurationHistogramTimer>();
   }
 }
 
 bool LayerTreeHostImpl::CanDraw() const {
   // Note: If you are changing this function or any other function that might
   // affect the result of CanDraw, make sure to call
   // client_->OnCanDrawStateChanged in the proper places and update the
   // NotifyIfCanDrawChanged test.
 
   if (!layer_tree_frame_sink_) {
@@ skipping 969 matching lines @@
   if (!result.IsValid())
     result = gfx::ColorSpace::CreateSRGB();
   return result;
 }
 
 void LayerTreeHostImpl::RequestImplSideInvalidation() {
   client_->NeedsImplSideInvalidation();
 }
 
 void LayerTreeHostImpl::NotifyReadyToActivate() {
+  pending_tree_raster_duration_timer_.reset();
   client_->NotifyReadyToActivate();
 }
 
 void LayerTreeHostImpl::NotifyReadyToDraw() {
   // Tiles that are ready will cause NotifyTileStateChanged() to be called so we
   // don't need to schedule a draw here. Just stop WillBeginImplFrame() from
   // causing optimistic requests to draw a frame.
   is_likely_to_require_a_draw_ = false;
 
   client_->NotifyReadyToDraw();
@@ skipping 2925 matching lines @@
 
 void LayerTreeHostImpl::ShowScrollbarsForImplScroll(ElementId element_id) {
   if (!element_id)
     return;
   if (ScrollbarAnimationController* animation_controller =
           ScrollbarAnimationControllerForElementId(element_id))
     animation_controller->DidScrollUpdate();
 }
 
 }  // namespace cc