Implement web content hit testing in win aura.

ui/views/accessibility/native_view_accessibility.h

Index: ui/views/accessibility/native_view_accessibility.h
diff --git a/ui/views/accessibility/native_view_accessibility.h b/ui/views/accessibility/native_view_accessibility.h
index 688f34cc64e5a8c19b34f74e3d4fd3f01c2eb856..2fc4c4423b6e53c63f1ab0c2e16460ff5ca00cb4 100644
--- a/ui/views/accessibility/native_view_accessibility.h
+++ b/ui/views/accessibility/native_view_accessibility.h
@@ -13,13 +13,6 @@ namespace views {
 
 class View;
 
-class AccessibleWebView {
- public:
-  virtual gfx::NativeViewAccessible AccessibleObjectFromChildId(long child_id)
-      = 0;
-  virtual View* AsView() = 0;
-};
-
 class VIEWS_EXPORT NativeViewAccessibility {
  public:
   static NativeViewAccessibility* Create(View* view);
@@ -33,9 +26,11 @@ class VIEWS_EXPORT NativeViewAccessibility {
   // use reference counting.
   virtual void Destroy();
 
-  static void RegisterWebView(AccessibleWebView* web_view);
-
-  static void UnregisterWebView(AccessibleWebView* web_view);
+  // WebViews need to be registered because they implement their own
+  // tree of accessibility objects, and we need to check them when
+  // mapping a child id to a NativeViewAccessible.
+  static void RegisterWebView(View* web_view);
+  static void UnregisterWebView(View* web_view);
 
  protected:
   NativeViewAccessibility();