Fire ax focus on root document when root changes.

BUG=347448

Review URL: https://codereview.chromium.org/227773002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262343 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/content/browser/accessibility/browser_accessibility_manager_win.h b/content/browser/accessibility/browser_accessibility_manager_win.h
index 67508266..3fbbd3f 100644
--- a/content/browser/accessibility/browser_accessibility_manager_win.h
+++ b/content/browser/accessibility/browser_accessibility_manager_win.h
@@ -63,6 +63,10 @@
   // Called when |accessible_hwnd_| is deleted by its parent.
   void OnAccessibleHwndDeleted();
 
+ protected:
+  // BrowserAccessibilityManager methods
+  virtual void OnRootChanged() OVERRIDE;
+
  private:
   // The closest ancestor HWND.
   HWND parent_hwnd_;