Add Mojo API for Blink hit testing

third_party/WebKit/Source/core/exported/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 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 2084 matching lines @@
       ->HorizontalScrollbar();
 }
 
 bool WebViewImpl::HasVerticalScrollbar() {
   return MainFrameImpl()
       ->GetFrameView()
       ->LayoutViewportScrollableArea()
       ->VerticalScrollbar();
 }
 
+// WebFrame* WebViewImpl::HitTestFrameAt(const WebFloatPoint& point) {
+//  if (!MainFrameImpl())
+//    return nullptr;
+//
+//  HitTestResult hit_test_result =
+//      MainFrameImpl()->GetFrame()->GetEventHandler().HitTestResultAtPoint(
+//          LayoutPoint((FloatPoint)point));
+//  Frame* target_frame = nullptr;
+//  Node* target_node = hit_test_result.InnerNode();
+//  if (target_node->IsFrameOwnerElement())
+//    target_frame = ToHTMLFrameOwnerElement(target_node)->ContentFrame();
+//  else
+//    target_frame = target_node->GetDocument().GetFrame();
+//  return WebFrame::FromFrame(target_frame);
+//}
+
 WebInputEventResult WebViewImpl::HandleInputEvent(
     const WebCoalescedInputEvent& coalesced_event) {
   const WebInputEvent& input_event = coalesced_event.Event();
   // TODO(dcheng): The fact that this is getting called when there is no local
   // main frame is problematic and probably indicates a bug in the input event
   // routing code.
   if (!MainFrameImpl())
     return WebInputEventResult::kNotHandled;
 
   GetPage()->GetVisualViewport().StartTrackingPinchStats();
@@ skipping 1977 matching lines @@
   if (focused_frame->LocalFrameRoot() != MainFrameImpl()->GetFrame())
     return nullptr;
   return focused_frame;
 }
 
 LocalFrame* WebViewImpl::FocusedLocalFrameAvailableForIme() const {
   return ime_accept_events_ ? FocusedLocalFrameInWidget() : nullptr;
 }
 
 }  // namespace blink