gesture recognizer: Remove the touch-event queue.

content/browser/renderer_host/touch_event_queue.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_TOUCH_EVENT_QUEUE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_TOUCH_EVENT_QUEUE_H_
 
 #include <deque>
 
 #include "base/basictypes.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
 
+class MockRenderWidgetHost;
+
 namespace content {
 
 class RenderWidgetHostImpl;
 
 // A queue for throttling and coalescing touch-events.
 class TouchEventQueue {
  public:
   explicit TouchEventQueue(RenderWidgetHostImpl* host);
   virtual ~TouchEventQueue();
 
   // Adds an event to the queue. The event may be coalesced with previously
   // queued events (e.g. consecutive touch-move events can be coalesced into a
   // single touch-move event). The event may also be immediately forwarded to
   // the renderer (e.g. when there are no other queued touch event).
   void QueueEvent(const WebKit::WebTouchEvent& event);
 
   // Notifies the queue that a touch-event has been processed by the renderer.
   // At this point, the queue may send one or more gesture events and/or
   // additional queued touch-events to the renderer.
   void ProcessTouchAck(bool processed);
 
+  // Empties the queue of touch events. This may result in any number of gesture
+  // events being sent to the renderer.
+  void FlushQueue();
+
+  // Resets all internal state. This does not trigger any touch or gesture
+  // events to be sent.
+  void Reset();
+
+  // Returns whether the event-queue is empty.
+  bool empty() const WARN_UNUSED_RESULT {
+    return touch_queue_.empty();
+  }
+
  private:
+  friend class ::MockRenderWidgetHost;
+
+  // Pops the touch-event from the top of the queue and sends it to the
+  // RenderWidgetHostView. This reduces the size of the queue by one.
+  void PopTouchEventToView(bool processed);
+
+  bool CoalesceIfPossible(const WebKit::WebTouchEvent& event);
+
   // The RenderWidgetHost that owns this event-queue.
   RenderWidgetHostImpl* render_widget_host_;
 
   typedef std::deque<WebKit::WebTouchEvent> TouchQueue;
   TouchQueue touch_queue_;
 
   DISALLOW_COPY_AND_ASSIGN(TouchEventQueue);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_TOUCH_EVENT_QUEUE_H_