Adds MSAA/IAccessible exposure of web content.

chrome/browser/render_widget_host_hwnd.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef CHROME_BROWSER_RENDER_WIDGET_HOST_CONTAINER_H__
 #define CHROME_BROWSER_RENDER_WIDGET_HOST_CONTAINER_H__
 
 #include <atlbase.h>
 #include <atlapp.h>
 #include <atlcrack.h>
@@ skipping 89 matching lines @@
     MESSAGE_HANDLER(WM_SYSKEYUP, OnKeyEvent)
     MESSAGE_HANDLER(WM_KEYDOWN, OnKeyEvent)
     MESSAGE_HANDLER(WM_KEYUP, OnKeyEvent)
     MESSAGE_HANDLER(WM_MOUSEWHEEL, OnWheelEvent)
     MESSAGE_HANDLER(WM_HSCROLL, OnWheelEvent)
     MESSAGE_HANDLER(WM_VSCROLL, OnWheelEvent)
     MESSAGE_HANDLER(WM_CHAR, OnKeyEvent)
     MESSAGE_HANDLER(WM_SYSCHAR, OnKeyEvent)
     MESSAGE_HANDLER(WM_IME_CHAR, OnKeyEvent)
     MESSAGE_HANDLER(WM_MOUSEACTIVATE, OnMouseActivate)
+    MESSAGE_HANDLER(WM_GETOBJECT, OnGetObject)
   END_MSG_MAP()
 
   // Overridden from RenderWidgetHostView:
   virtual void DidBecomeSelected();
   virtual void WasHidden();
   virtual void SetSize(const gfx::Size& size);
   virtual HWND GetPluginHWND();
   virtual void ForwardMouseEventToRenderer(UINT message,
                                            WPARAM wparam,
                                            LPARAM lparam);
@@ skipping 37 matching lines @@
       UINT message, WPARAM wparam, LPARAM lparam, BOOL& handled);
   LRESULT OnImeEndComposition(
       UINT message, WPARAM wparam, LPARAM lparam, BOOL& handled);
   LRESULT OnMouseEvent(
       UINT message, WPARAM wparam, LPARAM lparam, BOOL& handled);
   LRESULT OnKeyEvent(
       UINT message, WPARAM wparam, LPARAM lparam, BOOL& handled);
   LRESULT OnWheelEvent(
       UINT message, WPARAM wparam, LPARAM lparam, BOOL& handled);
   LRESULT OnMouseActivate(UINT, WPARAM, LPARAM, BOOL& handled);
+  // Handle MSAA requests for accessibility information.
+  LRESULT OnGetObject(UINT message, WPARAM wparam, LPARAM lparam,
+                      BOOL& handled);
   // Handle vertical scrolling
   LRESULT OnVScroll(int code, short position, HWND scrollbar_control);
   // Handle horizontal scrolling
   LRESULT OnHScroll(int code, short position, HWND scrollbar_control);
 
   void OnFinalMessage(HWND window);
 
  private:
   // Tells Windows that we want to hear about mouse exit messages.
   void TrackMouseLeave(bool start_tracking);
@@ skipping 62 matching lines @@
   bool tooltip_showing_;
 
   // Factory used to safely scope delayed calls to ShutdownHost().
   ScopedRunnableMethodFactory<RenderWidgetHostHWND> shutdown_factory_;
 
   // Our parent HWND.  We keep a reference to it as we SetParent(NULL) when
   // hidden to prevent getting messages (Paint, Resize...), and we reattach
   // when shown again.
   HWND parent_hwnd_;
 
+  // Instance of accessibility information for the root of the MSAA
+  // tree representation of the WebKit render tree.
+  CComPtr<IAccessible> browser_accessibility_root_;
+
   // The time at which this view started displaying white pixels as a result of
   // not having anything to paint (empty backing store from renderer). This
   // value returns true for is_null() if we are not recording whiteout times.
   TimeTicks whiteout_start_time_;
 
   DISALLOW_EVIL_CONSTRUCTORS(RenderWidgetHostHWND);
 };
 
 #endif  // #ifndef CHROME_BROWSER_RENDER_WIDGET_HOST_CONTAINER_H__