Remove ObserveWheelEventAndResult callbacks since they are now gesture based.

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 543 matching lines @@
         // main thread. Change back to DROP_EVENT once we have synchronization
         // bugs sorted out.
         result = DID_NOT_HANDLE;
         break;
       case cc::InputHandler::SCROLL_UNKNOWN:
       case cc::InputHandler::SCROLL_ON_MAIN_THREAD:
         result = DID_NOT_HANDLE;
         break;
     }
   }
-
-  // Send the event and its disposition to the elasticity controller to update
-  // the over-scroll animation. If the event is to be handled on the main
-  // thread, the event and its disposition will be sent to the elasticity
-  // controller after being handled on the main thread.
-  if (scroll_elasticity_controller_ && result != DID_NOT_HANDLE) {
-    // Note that the call to the elasticity controller is made asynchronously,
-    // to minimize divergence between main thread and impl thread event
-    // handling paths.
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(&InputScrollElasticityController::ObserveWheelEventAndResult,
-                   scroll_elasticity_controller_->GetWeakPtr(), wheel_event,
-                   scroll_result));
-  }
   return result;
 }
 
 InputHandlerProxy::EventDisposition InputHandlerProxy::HandleGestureScrollBegin(
     const WebGestureEvent& gesture_event) {
   if (gesture_scroll_on_impl_thread_)
     CancelCurrentFling();
 
 #ifndef NDEBUG
   DCHECK(!expect_scroll_update_end_);
@@ skipping 766 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