cc: Delay start of scrollbar animation setNeedsRedraw.

cc/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/layer_tree_host_impl.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
@@ skipping 1542 matching lines @@
 
 void LayerTreeHostImpl::ClearCurrentlyScrollingLayer() {
   active_tree_->ClearCurrentlyScrollingLayer();
   did_lock_scrolling_layer_ = false;
 }
 
 void LayerTreeHostImpl::ScrollEnd() {
   if (top_controls_manager_)
     top_controls_manager_->ScrollEnd();
   ClearCurrentlyScrollingLayer();
+  StartScrollbarAnimation(base::TimeTicks::Now());
 }
 
 void LayerTreeHostImpl::PinchGestureBegin() {
   pinch_gesture_active_ = true;
   previous_pinch_anchor_ = gfx::Point();
   client_->RenewTreePriority();
 }
 
 void LayerTreeHostImpl::PinchGestureUpdate(float magnify_delta,
                                            gfx::Point anchor) {
@@ skipping 25 matching lines @@
   }
 
   client_->SetNeedsCommitOnImplThread();
   client_->SetNeedsRedrawOnImplThread();
   client_->RenewTreePriority();
 }
 
 void LayerTreeHostImpl::PinchGestureEnd() {
   pinch_gesture_active_ = false;
 
-  if (RootScrollLayer() &&
-      RootScrollLayer()->scrollbar_animation_controller()) {
-    RootScrollLayer()->scrollbar_animation_controller()->
-        didPinchGestureEnd(base::TimeTicks::Now());
-  }
-
   client_->SetNeedsCommitOnImplThread();
 }
 
 static void CollectScrollDeltas(ScrollAndScaleSet* scroll_info,
                                 LayerImpl* layer_impl) {
   if (!layer_impl)
     return;
 
   gfx::Vector2d scroll_delta =
       gfx::ToFlooredVector2d(layer_impl->scroll_delta());
@@ skipping 199 matching lines @@
   AnimateScrollbarsRecursive(active_tree_->root_layer(), time);
 }
 
 void LayerTreeHostImpl::AnimateScrollbarsRecursive(LayerImpl* layer,
                                                    base::TimeTicks time) {
   if (!layer)
     return;
 
   ScrollbarAnimationController* scrollbar_controller =
       layer->scrollbar_animation_controller();
-  if (scrollbar_controller && scrollbar_controller->animate(time))
+  if (scrollbar_controller && scrollbar_controller->animate(time)) {
+    TRACE_EVENT_INSTANT0(
+        "cc", "LayerTreeHostImpl::setNeedsRedraw due to AnimateScrollbars");
     client_->SetNeedsRedrawOnImplThread();
+  }
 
   for (size_t i = 0; i < layer->children().size(); ++i)
     AnimateScrollbarsRecursive(layer->children()[i], time);
 }
 
+void LayerTreeHostImpl::StartScrollbarAnimation(base::TimeTicks time) {
+  TRACE_EVENT0("cc", "LayerTreeHostImpl::startScrollbarAnimation");
+  StartScrollbarAnimationRecursive(RootLayer(), time);
+}
+
+void LayerTreeHostImpl::StartScrollbarAnimationRecursive(LayerImpl* layer,
+                                                         base::TimeTicks time) {
+  if (!layer)
+    return;
+
+  ScrollbarAnimationController* scrollbar_controller =
+      layer->scrollbar_animation_controller();
+  if (scrollbar_controller && layer != CurrentlyScrollingLayer()) {
+    double delay = scrollbar_controller->secondsBeforeStart(time);
+    if (delay > 0)
+      client_->RequestScrollbarAnimationOnImplThread(delay);
+    else if (delay == 0 && scrollbar_controller->animate(time))
+      client_->SetNeedsRedrawOnImplThread();
+  }
+
+  for (size_t i = 0; i < layer->children().size(); ++i)
+    StartScrollbarAnimationRecursive(layer->children()[i], time);
+}
+
 void LayerTreeHostImpl::SetTreePriority(TreePriority priority) {
   if (!tile_manager_)
     return;
 
   GlobalStateThatImpactsTilePriority new_state(tile_manager_->GlobalState());
   if (new_state.tree_priority == priority)
     return;
 
   new_state.tree_priority = priority;
   tile_manager_->SetGlobalState(new_state);
@@ skipping 72 matching lines @@
     tile_manager_->SetRecordRenderingStats(debug_state_.recordRenderingStats());
 }
 
 void LayerTreeHostImpl::SavePaintTime(const base::TimeDelta& total_paint_time,
                                       int commit_number) {
   DCHECK(debug_state_.continuousPainting);
   paint_time_counter_->SavePaintTime(total_paint_time, commit_number);
 }
 
 }  // namespace cc