Resend unconsumed scroll update from guest back to embedder (WebView Scroll Bubble).

content/browser/renderer_host/input/gesture_event_queue.cc

 // Copyright 2014 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 "content/browser/renderer_host/input/gesture_event_queue.h"
 
 #include "base/trace_event/trace_event.h"
 #include "content/browser/renderer_host/input/touchpad_tap_suppression_controller.h"
 #include "content/browser/renderer_host/input/touchscreen_tap_suppression_controller.h"
 
@@ skipping 107 matching lines @@
             debounce_interval_,
             this,
             &GestureEventQueue::SendScrollEndingEventsNow);
       } else {
         // Extend the bounce interval.
         debounce_deferring_timer_.Reset();
       }
       scrolling_in_progress_ = true;
       debouncing_deferral_queue_.clear();
       return true;
+
     case WebInputEvent::GesturePinchBegin:
     case WebInputEvent::GesturePinchEnd:
     case WebInputEvent::GesturePinchUpdate:
       // TODO(rjkroege): Debounce pinch (http://crbug.com/147647)
       return true;
     default:
       if (scrolling_in_progress_) {
         debouncing_deferral_queue_.push_back(gesture_event);
         return false;
       }
@@ skipping 251 matching lines @@
     return 0;
 
   if (!ignore_next_ack_)
     return 1;
 
   DCHECK_GT(coalesced_gesture_events_.size(), 1U);
   return 2;
 }
 
 }  // namespace content