Use WTF::TimeTicks to represent timestamp in Platform/Core event types

third_party/WebKit/Source/platform/PlatformEvent.h

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 10 matching lines @@
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef PlatformEvent_h
 #define PlatformEvent_h
 
 #include "wtf/Allocator.h"
 #include "wtf/Noncopyable.h"
+#include "wtf/Time.h"
 
 namespace blink {
 
 class PlatformEvent {
  public:
   enum EventType {
     NoType = 0,
 
     // PlatformMouseEvent
     MouseMoved,
@@ skipping 90 matching lines @@
 
   EventType type() const { return static_cast<EventType>(m_type); }
 
   bool shiftKey() const { return m_modifiers & ShiftKey; }
   bool ctrlKey() const { return m_modifiers & CtrlKey; }
   bool altKey() const { return m_modifiers & AltKey; }
   bool metaKey() const { return m_modifiers & MetaKey; }
 
   Modifiers getModifiers() const { return static_cast<Modifiers>(m_modifiers); }
 
-  double timestamp() const { return m_timestamp; }
+  TimeTicks timestamp() const { return m_timestamp; }
 
  protected:
-  PlatformEvent() : m_type(NoType), m_modifiers(), m_timestamp(0) {}
+  PlatformEvent() : m_type(NoType), m_modifiers() {}
 
-  explicit PlatformEvent(EventType type)
-      : m_type(type), m_modifiers(0), m_timestamp(0) {}
+  explicit PlatformEvent(EventType type) : m_type(type), m_modifiers(0) {}
 
-  PlatformEvent(EventType type, Modifiers modifiers, double timestamp)
+  PlatformEvent(EventType type, Modifiers modifiers, TimeTicks timestamp)
       : m_type(type), m_modifiers(modifiers), m_timestamp(timestamp) {}
 
   // Explicit protected destructor so that people don't accidentally
   // delete a PlatformEvent.
   ~PlatformEvent() {}
 
   unsigned m_type;
   unsigned m_modifiers;
-  double m_timestamp;
+  TimeTicks m_timestamp;
 };
 
 }  // namespace blink
 
 #endif  // PlatformEvent_h