cc: Delay start of scrollbar animation setNeedsRedraw.

cc/layer_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_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "base/stringprintf.h"
 #include "base/values.h"
 #include "cc/animation_registrar.h"
@@ skipping 797 matching lines @@
   if (vertical_scrollbar_layer_) {
     vertical_scrollbar_layer_->SetCurrentPos(current_offset.y());
     vertical_scrollbar_layer_->SetTotalSize(bounds_.height());
     vertical_scrollbar_layer_->SetMaximum(max_scroll_offset_.y());
   }
 
   if (current_offset == last_scroll_offset_)
     return;
   last_scroll_offset_ = current_offset;
 
-  if (scrollbar_animation_controller_) {
-    scrollbar_animation_controller_->didUpdateScrollOffset(
+  if (scrollbar_animation_controller_ &&
+      !scrollbar_animation_controller_->isScrollGestureInProgress()) {
+    scrollbar_animation_controller_->didProgrammaticallyUpdateScroll(
         base::TimeTicks::Now());
   }
 
   // Get the current_offset_.y() value for a sanity-check on scrolling
   // benchmark metrics. Specifically, we want to make sure
   // BasicMouseWheelSmoothScrollGesture has proper scroll curves.
   if (layer_tree_impl()->IsActiveTree()) {
     TRACE_COUNTER_ID1("gpu", "scroll_offset_y", this->id(), current_offset.y());
   }
 }
@@ skipping 69 matching lines @@
 
 void LayerImpl::SetScrollbarOpacity(float opacity) {
   if (horizontal_scrollbar_layer_)
     horizontal_scrollbar_layer_->SetOpacity(opacity);
   if (vertical_scrollbar_layer_)
     vertical_scrollbar_layer_->SetOpacity(opacity);
 }
 
 inline scoped_ptr<ScrollbarAnimationController>
 CreateScrollbarAnimationControllerWithFade(LayerImpl* layer) {
-  double fadeout_delay = 0.3;
-  double fadeout_length = 0.3;
+  base::TimeDelta fadeout_delay = base::TimeDelta::FromMilliseconds(300);
+  base::TimeDelta fadeout_length = base::TimeDelta::FromMilliseconds(300);
   return ScrollbarAnimationControllerLinearFade::create(
       layer, fadeout_delay, fadeout_length)
       .PassAs<ScrollbarAnimationController>();
 }
 
 void LayerImpl::DidBecomeActive() {
   if (!layer_tree_impl_->settings().useLinearFadeScrollbarAnimator)
     return;
 
   bool need_scrollbar_animation_controller = horizontal_scrollbar_layer_ ||
@@ skipping 35 matching lines @@
 
 }
 
 scoped_ptr<base::Value> LayerImpl::AsValue() const {
   scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue());
   AsValueInto(state.get());
   return state.PassAs<base::Value>();
 }
 
 }  // namespace cc