[not for review - epic CL] Adding Elastic+Momentum+Layered scrolling to views::ScrollView

ui/events/blink/input_handler_proxy.cc

 // Copyright 2013 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 "ui/events/blink/input_handler_proxy.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 234 matching lines @@
       disallow_horizontal_fling_scroll_(false),
       disallow_vertical_fling_scroll_(false),
       has_fling_animation_started_(false),
       smooth_scroll_enabled_(false),
       uma_latency_reporting_enabled_(base::TimeTicks::IsHighResolution()),
       touch_start_result_(kEventDispositionUndefined),
       current_overscroll_params_(nullptr) {
   DCHECK(client);
   input_handler_->BindToClient(this);
   cc::ScrollElasticityHelper* scroll_elasticity_helper =
-      input_handler_->CreateScrollElasticityHelper();
+      input_handler_->CreateRootScrollElasticityHelper();
   if (scroll_elasticity_helper) {
-    scroll_elasticity_controller_.reset(
-        new InputScrollElasticityController(scroll_elasticity_helper));
+    scroll_elasticity_controller_.reset(new InputScrollElasticityController());
+    scroll_elasticity_controller_->SetActiveHelper(
+        scroll_elasticity_helper->GetWeakPtr());
   }
 }
 
 InputHandlerProxy::~InputHandlerProxy() {}
 
 void InputHandlerProxy::WillShutdown() {
   scroll_elasticity_controller_.reset();
   input_handler_ = NULL;
   client_->WillShutdown();
 }
@@ skipping 1122 matching lines @@
   // is made asynchronously, to minimize divergence between main thread and
   // impl thread event handling paths.
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,
       base::Bind(&InputScrollElasticityController::ObserveGestureEventAndResult,
                  scroll_elasticity_controller_->GetWeakPtr(), gesture_event,
                  scroll_result));
 }
 
 }  // namespace ui