CC Animation: Introduce some dirty flags to optimize PushProperties on commit

cc/animation/scroll_offset_animations.cc

 // Copyright 2016 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/animation/scroll_offset_animations.h"
 
 #include "cc/animation/animation_host.h"
 
 namespace cc {
 
@@ skipping 16 matching lines @@
              : iter->second;
 }
 
 void ScrollOffsetAnimations::AddAdjustmentUpdate(ElementId element_id,
                                                  gfx::Vector2dF adjustment) {
   DCHECK(element_id);
   ScrollOffsetAnimationUpdate update = GetUpdateForElementId(element_id);
   update.adjustment_ += adjustment;
   element_to_update_map_[element_id] = update;
   animation_host_->SetNeedsCommit();
+  animation_host_->SetNeedsPushProperties();
 }
 
 void ScrollOffsetAnimations::AddTakeoverUpdate(ElementId element_id) {
   DCHECK(element_id);
   ScrollOffsetAnimationUpdate update = GetUpdateForElementId(element_id);
   update.takeover_ = true;
   element_to_update_map_[element_id] = update;
   animation_host_->SetNeedsCommit();
+  animation_host_->SetNeedsPushProperties();
 }
 
 bool ScrollOffsetAnimations::HasUpdatesForTesting() const {
   return !element_to_update_map_.empty();
 }
 
 void ScrollOffsetAnimations::PushPropertiesTo(
     ScrollOffsetAnimationsImpl* animations) {
   DCHECK(animations);
   if (element_to_update_map_.empty())
     return;
 
   for (auto& kv : element_to_update_map_) {
     const auto& update = kv.second;
     if (update.takeover_)
       animations->ScrollAnimationAbort(true /*needs_completion*/);
     else
       animations->ScrollAnimationApplyAdjustment(update.element_id_,
                                                  update.adjustment_);
   }
   element_to_update_map_.clear();
 }
 
 }  // namespace cc