Fire accessibility hover events when the touch exploration flag is set.

third_party/WebKit/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 154 matching lines @@
 
         // Toggle modifiers for all events. Danger: these are not reflected
         // into WebCore, so round-tripping from WebInputEvent to a WebCore
         // event and back will not preserve these flags.
         CapsLockOn       = 1 << 9,
         NumLockOn        = 1 << 10,
 
         // Left/right modifiers for keyboard events.
         IsLeft           = 1 << 11,
         IsRight          = 1 << 12,
+
+        // Indicates that an event was generated on the touch screen while
+        // touch accessibility is enabled, so the event should be handled
+        // by accessibility code first before normal input event processing.
+        IsTouchAccessibility = 1 << 13
     };
 
     // The rail mode for a wheel event specifies the axis on which scrolling is
     // expected to stick. If this axis is set to Free, then scrolling is not
     // stuck to any axis.
     enum RailsMode {
         RailsModeFree       = 0,
         RailsModeHorizontal = 1,
         RailsModeVertical   = 2,
     };
@@ skipping 381 matching lines @@
         , uniqueTouchEventId(0)
     {
     }
 };
 
 #pragma pack(pop)
 
 } // namespace blink
 
 #endif