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

content/browser/renderer_host/legacy_render_widget_host_win.cc

 // Copyright (c) 2014 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/renderer_host/legacy_render_widget_host_win.h"
 
 #include <memory>
 
 #include "base/command_line.h"
 #include "base/win/win_util.h"
@@ skipping 167 matching lines @@
   if (!rwhi)
     return static_cast<LRESULT>(0L);
 
   BrowserAccessibilityManagerWin* manager =
       static_cast<BrowserAccessibilityManagerWin*>(
           rwhi->GetRootBrowserAccessibilityManager());
   if (!manager)
     return static_cast<LRESULT>(0L);
 
   base::win::ScopedComPtr<IAccessible> root(
-      ToBrowserAccessibilityWin(manager->GetRoot()));
+      ToBrowserAccessibilityWin(manager->GetRoot())->GetCOM());
   return LresultFromObject(IID_IAccessible, w_param,
       static_cast<IAccessible*>(root.Detach()));
 }
 
 // We send keyboard/mouse/touch messages to the parent window via SendMessage.
 // While this works, this has the side effect of converting input messages into
 // sent messages which changes their priority and could technically result
 // in these messages starving other messages in the queue. Additionally
 // keyboard/mouse hooks would not see these messages. The alternative approach
 // is to set and release capture as needed on the parent to ensure that it
@@ skipping 222 matching lines @@
       direct_manipulation_helper_->Activate(hwnd());
     } else if (window_pos->flags & SWP_HIDEWINDOW) {
       direct_manipulation_helper_->Deactivate(hwnd());
     }
   }
   SetMsgHandled(FALSE);
   return 0;
 }
 
 }  // namespace content