Split out the MSCOM pieces of BrowserAccessibilityWin into a seperate class.

content/browser/accessibility/browser_accessibility_manager_unittest.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 <stddef.h>
 #include <stdint.h>
 
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
@@ skipping 20 matching lines @@
   void NativeAddReference() override { native_ref_count_++; }
 
   void NativeReleaseReference() override {
     native_ref_count_--;
     if (native_ref_count_ == 0)
       delete this;
   }
 
   int native_ref_count_;
   static int global_obj_count_;
-
-#if defined(OS_WIN)
-  // Adds some padding to prevent a heap-buffer-overflow when an instance of
-  // this class is casted into a BrowserAccessibilityWin pointer.
-  // http://crbug.com/235508
-  // TODO(dmazzoni): Fix this properly.
-  static const size_t kDataSize = sizeof(int) + sizeof(BrowserAccessibility);
-  uint8_t padding_[sizeof(BrowserAccessibilityWin) - kDataSize];
-#endif
 };
 
 int CountedBrowserAccessibility::global_obj_count_ = 0;
 
 // Factory that creates a CountedBrowserAccessibility.
 class CountedBrowserAccessibilityFactory
     : public BrowserAccessibilityFactory {
  public:
   ~CountedBrowserAccessibilityFactory() override {}
   BrowserAccessibility* Create() override {
@@ skipping 1542 matching lines @@
   events2[0].event_type = ui::AX_EVENT_NONE;
   manager->OnAccessibilityEvents(events2);
 
   // Make sure that the focused node was updated to the new root and
   // that this doesn't crash.
   ASSERT_EQ(3, manager->GetRoot()->GetId());
   ASSERT_EQ(3, manager->GetFocus()->GetId());
 }
 
 }  // namespace content