Reduce hit test on ShowPress by moving event targeting to WebViewImpl

public/web/WebInputEvent.h

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 459 matching lines @@
 
     WebGestureEvent()
         : WebInputEvent(sizeof(WebGestureEvent))
         , x(0)
         , y(0)
         , globalX(0)
         , globalY(0)
     {
         memset(&data, 0, sizeof(data));
     }
+
+    bool isScrollEvent() const
+    {
+        switch (type) {
+        case GestureScrollBegin:
+        case GestureScrollEnd:
+        case GestureScrollUpdate:
+        case GestureScrollUpdateWithoutPropagation:
+        case GestureFlingStart:
+        case GestureFlingCancel:
+        case GesturePinchBegin:
+        case GesturePinchEnd:
+        case GesturePinchUpdate:
+            return true;
+        case GestureShowPress:
+        case GestureTap:
+        case GestureTapUnconfirmed:
+        case GestureTapDown:
+        case GestureTapCancel:
+        case GestureDoubleTap:
+        case GestureTwoFingerTap:
+        case GestureLongPress:
+        case GestureLongTap:
+            return false;
+        default:
+            BLINK_ASSERT_NOT_REACHED();
+            return false;
+        }
+    }
 };
 
 // WebTouchEvent --------------------------------------------------------------
 
 class WebTouchEvent : public WebInputEvent {
 public:
     // Maximum number of simultaneous touches supported on
     // Ash/Aura.
     enum { touchesLengthCap = 12 };
 
@@ skipping 22 matching lines @@
         , cancelable(true)
     {
     }
 };
 
 #pragma pack(pop)
 
 } // namespace blink
 
 #endif