cc: Make LayerAnimationController keep state for clearing scroll delta

cc/layers/layer_impl.cc

 // Copyright 2012 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/layers/layer_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "base/debug/trace_event_argument.h"
 #include "base/json/json_reader.h"
 #include "base/strings/stringprintf.h"
@@ skipping 42 matching lines @@
       double_sided_(true),
       should_flatten_transform_(true),
       layer_property_changed_(false),
       masks_to_bounds_(false),
       contents_opaque_(false),
       is_root_for_isolated_group_(false),
       use_parent_backface_visibility_(false),
       draw_checkerboard_for_missing_tiles_(false),
       draws_content_(false),
       hide_layer_and_subtree_(false),
-      clear_scroll_delta_at_activation_(false),
       transform_is_invertible_(true),
       is_container_for_fixed_position_layers_(false),
       background_color_(0),
       opacity_(1.0),
       blend_mode_(SkXfermode::kSrcOver_Mode),
       num_descendants_that_draw_content_(0),
       draw_depth_(0.f),
       needs_push_properties_(false),
       num_dependents_need_push_properties_(0),
       sorting_context_id_(0),
@@ skipping 276 matching lines @@
 void LayerImpl::SetSentScrollDelta(const gfx::Vector2dF& sent_scroll_delta) {
   // Pending tree never has sent scroll deltas
   DCHECK(layer_tree_impl()->IsActiveTree());
 
   if (sent_scroll_delta_ == sent_scroll_delta)
     return;
 
   sent_scroll_delta_ = sent_scroll_delta;
 }
 
-void LayerImpl::ClearScrollDeltaAtActivation() {
-  clear_scroll_delta_at_activation_ = true;
-}
-
 gfx::Vector2dF LayerImpl::ScrollBy(const gfx::Vector2dF& scroll) {
   gfx::Vector2dF adjusted_scroll = scroll;
   if (layer_tree_impl()->settings().use_pinch_virtual_viewport) {
     if (!user_scrollable_horizontal_)
       adjusted_scroll.set_x(0);
     if (!user_scrollable_vertical_)
       adjusted_scroll.set_y(0);
   }
   DCHECK(scrollable());
   gfx::Vector2dF min_delta = -ScrollOffsetToVector2dF(scroll_offset_);
@@ skipping 168 matching lines @@
   layer->SetTransformAndInvertibility(transform_, transform_is_invertible_);
 
   layer->SetScrollClipLayer(scroll_clip_layer_ ? scroll_clip_layer_->id()
                                                : Layer::INVALID_ID);
   layer->set_user_scrollable_horizontal(user_scrollable_horizontal_);
   layer->set_user_scrollable_vertical(user_scrollable_vertical_);
 
   // Save the difference but clear the sent delta so that we don't subtract
   // it again in SetScrollOffsetAndDelta's pending twin mirroring logic.
   gfx::Vector2dF remaining_delta =
-      clear_scroll_delta_at_activation_
+      layer_animation_controller_->scroll_offset_animation_was_interrupted()
           ? gfx::Vector2dF()
           : layer->ScrollDelta() - layer->sent_scroll_delta();
-  clear_scroll_delta_at_activation_ = false;
 
   layer->SetSentScrollDelta(gfx::Vector2dF());
   layer->SetScrollOffsetAndDelta(scroll_offset_, remaining_delta);
 
   layer->Set3dSortingContextId(sorting_context_id_);
   layer->SetNumDescendantsThatDrawContent(num_descendants_that_draw_content_);
 
   LayerImpl* scroll_parent = nullptr;
   if (scroll_parent_) {
     scroll_parent = layer->layer_tree_impl()->LayerById(scroll_parent_->id());
@@ skipping 218 matching lines @@
   if (!IsActive())
     return;
 
   SetScrollDelta(scroll_offset.DeltaFrom(scroll_offset_));
 
   layer_tree_impl_->DidAnimateScrollOffset();
 }
 
 void LayerImpl::OnAnimationWaitingForDeletion() {}
 
-void LayerImpl::OnScrollOffsetAnimationRemoved() {
-}
-
 bool LayerImpl::IsActive() const {
   return layer_tree_impl_->IsActiveTree();
 }
 
 gfx::Size LayerImpl::bounds() const {
   gfx::Vector2d delta = gfx::ToCeiledVector2d(bounds_delta_);
   return gfx::Size(bounds_.width() + delta.x(),
                    bounds_.height() + delta.y());
 }
 
@@ skipping 360 matching lines @@
 
 gfx::Vector2dF LayerImpl::ScrollDelta() const {
   if (scroll_offset_delegate_) {
     return scroll_offset_delegate_->GetTotalScrollOffset().DeltaFrom(
         scroll_offset_);
   }
   return scroll_delta_;
 }
 
 void LayerImpl::SetScrollDelta(const gfx::Vector2dF& scroll_delta) {
-  if (!IsActive() && clear_scroll_delta_at_activation_)
-    return;
   SetScrollOffsetAndDelta(scroll_offset_, scroll_delta);
 }
 
 gfx::ScrollOffset LayerImpl::TotalScrollOffset() const {
   return ScrollOffsetWithDelta(scroll_offset_, ScrollDelta());
 }
 
 void LayerImpl::SetDoubleSided(bool double_sided) {
   if (double_sided_ == double_sided)
     return;
@@ skipping 406 matching lines @@
   SetNeedsPushProperties();
   layer_tree_impl()->set_needs_update_draw_properties();
   if (should_have_render_surface) {
     render_surface_ = make_scoped_ptr(new RenderSurfaceImpl(this));
     return;
   }
   render_surface_.reset();
 }
 
 }  // namespace cc