Implement caching asynchronous accessibility hit testing.

content/browser/accessibility/browser_accessibility_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/accessibility/browser_accessibility_win.h"
 
 #include <UIAutomationClient.h>
 #include <UIAutomationCoreApi.h>
 
 #include <algorithm>
@@ skipping 427 matching lines @@
   if (!child)
     return E_INVALIDARG;
 
   gfx::Point point(x_left, y_top);
   if (!GetScreenBoundsRect().Contains(point)) {
     // Return S_FALSE and VT_EMPTY when outside the object's boundaries.
     child->vt = VT_EMPTY;
     return S_FALSE;
   }
 
-  BrowserAccessibility* result = BrowserAccessibilityForPoint(point);
+  BrowserAccessibility* result = manager()->CachingAsyncHitTest(point);
   if (result == this) {
     // Point is within this object.
     child->vt = VT_I4;
     child->lVal = CHILDID_SELF;
   } else {
     child->vt = VT_DISPATCH;
     child->pdispVal = ToBrowserAccessibilityWin(result)->NewReference();
   }
   return S_OK;
 }
@@ skipping 5069 matching lines @@
   return static_cast<BrowserAccessibilityWin*>(obj);
 }
 
 const BrowserAccessibilityWin*
 ToBrowserAccessibilityWin(const BrowserAccessibility* obj) {
   DCHECK(!obj || obj->IsNative());
   return static_cast<const BrowserAccessibilityWin*>(obj);
 }
 
 }  // namespace content