Remove PlatformEvent it is no longer used.

third_party/WebKit/Source/core/events/MouseEvent.cpp

Index: third_party/WebKit/Source/core/events/MouseEvent.cpp
diff --git a/third_party/WebKit/Source/core/events/MouseEvent.cpp b/third_party/WebKit/Source/core/events/MouseEvent.cpp
index 5e68f976bc08bcaa534d47ce6c7076a1334c0534..d23876e392cdaa33cb8352eda3b5f793e0d15bd2 100644
--- a/third_party/WebKit/Source/core/events/MouseEvent.cpp
+++ b/third_party/WebKit/Source/core/events/MouseEvent.cpp
@@ -106,7 +106,7 @@ MouseEvent* MouseEvent::create(const AtomicString& eventType,
                                AbstractView* view,
                                Event* underlyingEvent,
                                SimulatedClickCreationScope creationScope) {
-  PlatformEvent::Modifiers modifiers = PlatformEvent::NoModifiers;
+  WebInputEvent::Modifiers modifiers = WebInputEvent::NoModifiers;
   if (UIEventWithKeyState* keyStateEvent =
           findEventWithKeyState(underlyingEvent)) {
     modifiers = keyStateEvent->modifiers();
@@ -161,7 +161,7 @@ MouseEvent::MouseEvent(const AtomicString& eventType,
           cancelable,
           abstractView,
           detail,
-          static_cast<PlatformEvent::Modifiers>(event.modifiers()),
+          static_cast<WebInputEvent::Modifiers>(event.modifiers()),
           TimeTicks::FromSeconds(event.timeStampSeconds()),
           event.fromTouch()
               ? InputDeviceCapabilities::firesTouchEventsSourceCapabilities()
@@ -171,7 +171,7 @@ MouseEvent::MouseEvent(const AtomicString& eventType,
       m_movementDelta(flooredIntPoint(event.movementInRootFrame())),
       m_positionType(PositionType::Position),
       m_button(static_cast<short>(event.button)),
-      m_buttons(platformModifiersToButtons(event.modifiers())),
+      m_buttons(webInputEventModifiersToButtons(event.modifiers())),
       m_relatedTarget(relatedTarget),
       m_syntheticEventType(event.fromTouch() ? FromTouch
                                              : RealOrIndistinguishable),
@@ -192,7 +192,7 @@ MouseEvent::MouseEvent(const AtomicString& eventType,
                        int windowY,
                        int movementX,
                        int movementY,
-                       PlatformEvent::Modifiers modifiers,
+                       WebInputEvent::Modifiers modifiers,
                        short button,
                        unsigned short buttons,
                        EventTarget* relatedTarget,
@@ -287,15 +287,15 @@ void MouseEvent::initCoordinatesFromRootFrame(int windowX, int windowY) {
 
 MouseEvent::~MouseEvent() {}
 
-unsigned short MouseEvent::platformModifiersToButtons(unsigned modifiers) {
+unsigned short MouseEvent::webInputEventModifiersToButtons(unsigned modifiers) {
   unsigned short buttons = 0;
 
-  if (modifiers & PlatformEvent::LeftButtonDown)
+  if (modifiers & WebInputEvent::LeftButtonDown)
     buttons |= static_cast<unsigned short>(WebPointerProperties::Buttons::Left);
-  if (modifiers & PlatformEvent::RightButtonDown)
+  if (modifiers & WebInputEvent::RightButtonDown)
     buttons |=
         static_cast<unsigned short>(WebPointerProperties::Buttons::Right);
-  if (modifiers & PlatformEvent::MiddleButtonDown)
+  if (modifiers & WebInputEvent::MiddleButtonDown)
     buttons |=
         static_cast<unsigned short>(WebPointerProperties::Buttons::Middle);
 
@@ -342,7 +342,7 @@ void MouseEvent::initMouseEventInternal(
     int screenY,
     int clientX,
     int clientY,
-    PlatformEvent::Modifiers modifiers,
+    WebInputEvent::Modifiers modifiers,
     short button,
     EventTarget* relatedTarget,
     InputDeviceCapabilities* sourceCapabilities,