Prevent partial touch sequences from reaching the renderer

content/browser/renderer_host/input/input_router_impl.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 "content/browser/renderer_host/input/input_router_impl.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 483 matching lines @@
 void InputRouterImpl::OnSelectRangeAck() {
   select_range_pending_ = false;
   if (next_selection_range_)
     SendSelectRange(next_selection_range_.Pass());
 }
 
 void InputRouterImpl::OnHasTouchEventHandlers(bool has_handlers) {
   TRACE_EVENT1("input", "InputRouterImpl::OnHasTouchEventHandlers",
                "has_handlers", has_handlers);
 
-  if (has_handlers == touch_event_queue_->has_handlers())
-    return;
   touch_event_queue_->OnHasTouchEventHandlers(has_handlers);
   client_->OnHasTouchEventHandlers(has_handlers);
 }
 
 void InputRouterImpl::OnSetTouchAction(
     content::TouchAction touch_action) {
   // Synthetic touchstart events should get filtered out in RenderWidget.
   DCHECK(touch_event_queue_->IsPendingAckTouchStart());
 
   touch_action_filter_.OnSetTouchAction(touch_action);
@@ skipping 205 matching lines @@
       break;
   }
 }
 
 bool InputRouterImpl::IsInOverscrollGesture() const {
   OverscrollController* controller = client_->GetOverscrollController();
   return controller && controller->overscroll_mode() != OVERSCROLL_NONE;
 }
 
 }  // namespace content