Update from https://crrev.com/307330

cc/trees/layer_tree_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_impl.h"
 
 #include <limits>
 #include <set>
 
 #include "base/debug/trace_event.h"
@@ skipping 57 matching lines @@
 
  private:
   LayerImpl* layer_;
   LayerScrollOffsetDelegate* delegate_;
   LayerTreeImpl* layer_tree_impl_;
   gfx::ScrollOffset last_set_scroll_offset_;
 };
 
 LayerTreeImpl::LayerTreeImpl(
     LayerTreeHostImpl* layer_tree_host_impl,
-    scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor)
+    scoped_refptr<SyncedProperty<ScaleGroup>> page_scale_factor,
+    scoped_refptr<SyncedElasticOverscroll> elastic_overscroll)
     : layer_tree_host_impl_(layer_tree_host_impl),
       source_frame_number_(-1),
       hud_layer_(0),
       currently_scrolling_layer_(NULL),
       root_layer_scroll_offset_delegate_(NULL),
       background_color_(0),
       has_transparent_background_(false),
+      overscroll_elasticity_layer_(NULL),
       page_scale_layer_(NULL),
       inner_viewport_scroll_layer_(NULL),
       outer_viewport_scroll_layer_(NULL),
       page_scale_factor_(page_scale_factor),
       min_page_scale_factor_(0),
       max_page_scale_factor_(0),
+      elastic_overscroll_(elastic_overscroll),
       scrolling_layer_id_from_previous_tree_(0),
       contents_textures_purged_(false),
       viewport_size_invalid_(false),
       needs_update_draw_properties_(true),
       needs_full_tree_sync_(true),
       next_activation_forces_redraw_(false),
       has_ever_been_drawn_(false),
       render_surface_layer_list_id_(0),
       top_controls_shrink_blink_size_(false),
       top_controls_height_(0),
@@ skipping 121 matching lines @@
   target_tree->top_controls_content_offset_ = top_controls_content_offset_;
   target_tree->top_controls_delta_ = target_tree->top_controls_delta_ -
                                      target_tree->sent_top_controls_delta_ -
                                      top_controls_height_delta;
   target_tree->sent_top_controls_delta_ = 0.f;
 
   // Active tree already shares the page_scale_factor object with pending
   // tree so only the limits need to be provided.
   target_tree->PushPageScaleFactorAndLimits(nullptr, min_page_scale_factor(),
                                             max_page_scale_factor());
+  target_tree->elastic_overscroll()->PushPendingToActive();
 
   target_tree->pending_page_scale_animation_ =
       pending_page_scale_animation_.Pass();
 
   if (page_scale_layer_ && inner_viewport_scroll_layer_) {
     target_tree->SetViewportLayersFromIds(
         overscroll_elasticity_layer_ ? overscroll_elasticity_layer_->id()
                                      : Layer::INVALID_ID,
         page_scale_layer_->id(), inner_viewport_scroll_layer_->id(),
         outer_viewport_scroll_layer_ ? outer_viewport_scroll_layer_->id()
@@ skipping 178 matching lines @@
 }
 
 static void ApplySentScrollDeltasFromAbortedCommitTo(LayerImpl* layer) {
   layer->ApplySentScrollDeltasFromAbortedCommit();
 }
 
 void LayerTreeImpl::ApplySentScrollAndScaleDeltasFromAbortedCommit() {
   DCHECK(IsActiveTree());
 
   page_scale_factor()->AbortCommit();
+  elastic_overscroll()->AbortCommit();
 
   top_controls_content_offset_ += sent_top_controls_delta_;
   top_controls_delta_ -= sent_top_controls_delta_;
   sent_top_controls_delta_ = 0.f;
 
   if (!root_layer())
     return;
 
   LayerTreeHostCommon::CallFunctionForSubtree(
       root_layer(), base::Bind(&ApplySentScrollDeltasFromAbortedCommitTo));
@@ skipping 76 matching lines @@
         page_scale_layer_ ? page_scale_layer_ : InnerViewportContainerLayer();
     bool can_render_to_separate_surface =
         (layer_tree_host_impl_->GetDrawMode() !=
          DRAW_MODE_RESOURCELESS_SOFTWARE);
 
     ++render_surface_layer_list_id_;
     LayerTreeHostCommon::CalcDrawPropsImplInputs inputs(
         root_layer(), DrawViewportSize(),
         layer_tree_host_impl_->DrawTransform(), device_scale_factor(),
         current_page_scale_factor(), page_scale_layer,
-        resource_provider()->max_texture_size(), settings().can_use_lcd_text,
-        settings().layers_always_allowed_lcd_text,
+        elastic_overscroll()->Current(IsActiveTree()),
+        overscroll_elasticity_layer_, resource_provider()->max_texture_size(),
+        settings().can_use_lcd_text, settings().layers_always_allowed_lcd_text,
         can_render_to_separate_surface,
         settings().layer_transforms_should_scale_layer_contents,
         &render_surface_layer_list_, render_surface_layer_list_id_);
     LayerTreeHostCommon::CalculateDrawProperties(&inputs);
   }
 
   {
     TRACE_EVENT_BEGIN2("cc", "LayerTreeImpl::UpdateTilePriorities", "IsActive",
                        IsActiveTree(), "SourceFrameNumber",
                        source_frame_number_);
@@ skipping 974 matching lines @@
     scoped_ptr<PendingPageScaleAnimation> pending_animation) {
   pending_page_scale_animation_ = pending_animation.Pass();
 }
 
 scoped_ptr<PendingPageScaleAnimation>
     LayerTreeImpl::TakePendingPageScaleAnimation() {
   return pending_page_scale_animation_.Pass();
 }
 
 }  // namespace cc