Touch emulator: allow multiple touch streams.

content/common/input/web_touch_event_traits.h

 // 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.
 
 #ifndef CONTENT_COMMON_INPUT_WEB_TOUCH_EVENT_TRAITS_H_
 #define CONTENT_COMMON_INPUT_WEB_TOUCH_EVENT_TRAITS_H_
 
 #include "base/basictypes.h"
 #include "content/common/input/scoped_web_input_event.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 
 namespace content {
 
 // Utility class for performing operations on and with WebTouchEvents.
 class CONTENT_EXPORT WebTouchEventTraits {
  public:
   // Returns whether all touches in the event have the specified state.
   static bool AllTouchPointsHaveState(const blink::WebTouchEvent& event,
                                       blink::WebTouchPoint::State state);
 
   // Returns whether this event represents a transition from no active
   // touches to some active touches (the start of a new "touch sequence").
   static bool IsTouchSequenceStart(const blink::WebTouchEvent& event);
 
+  // Returns whether this event represents a transition from active
+  // touches to no active touches (the end of a "touch sequence").
+  static bool IsTouchSequenceEnd(const blink::WebTouchEvent& event);
+
   // Sets the type of |event| to |type|, resetting any other type-specific
   // properties and updating the timestamp.
   static void ResetType(blink::WebInputEvent::Type type,
                         double timestamp_sec,
                         blink::WebTouchEvent* event);
 
   // Like ResetType but also resets the state of all active touches
   // to match the event type.  This is particularly useful, for example,
   // in sending a touchcancel for all active touches.
   static void ResetTypeAndTouchStates(blink::WebInputEvent::Type type,
                                       double timestamp_sec,
                                       blink::WebTouchEvent* event);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_INPUT_WEB_TOUCH_EVENT_TRAITS_H_