Fix race in BrowserAccessibilityManagerWin creation.

ui/views/controls/webview/webview.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 "ui/views/controls/webview/webview.h"
 
 #include "content/public/browser/browser_accessibility_state.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/render_view_host.h"
@@ skipping 280 matching lines @@
   if (holder_->native_view() == view_to_attach)
     return;
   holder_->Attach(view_to_attach);
 
   // The view will not be focused automatically when it is attached, so we need
   // to pass on focus to it if the FocusManager thinks the view is focused. Note
   // that not every Widget has a focus manager.
   FocusManager* const focus_manager = GetFocusManager();
   if (focus_manager && focus_manager->GetFocusedView() == this)
     OnFocus();
-
-#if defined(OS_WIN)
-  if (!is_embedding_fullscreen_widget_) {
-    web_contents()->SetParentNativeViewAccessible(
-        parent()->GetNativeViewAccessible());
-  }
-#endif
 }
 
 void WebView::DetachWebContents() {
-  if (web_contents()) {
+  if (web_contents())
     holder_->Detach();
-#if defined(OS_WIN)
-    if (!is_embedding_fullscreen_widget_)
-      web_contents()->SetParentNativeViewAccessible(NULL);
-#endif
-  }
 }
 
 void WebView::ReattachForFullscreenChange(bool enter_fullscreen) {
   DCHECK(embed_fullscreen_widget_mode_enabled_);
   const bool web_contents_has_separate_fs_widget =
       web_contents() && web_contents()->GetFullscreenRenderWidgetHostView();
   if (is_embedding_fullscreen_widget_ || web_contents_has_separate_fs_widget) {
     // Shutting down or starting up the embedding of the separate fullscreen
     // widget.  Need to detach and re-attach to a different native view.
     DetachWebContents();
@@ skipping 26 matching lines @@
   if (!contents) {
     content::WebContents::CreateParams create_params(
         browser_context, NULL);
     return content::WebContents::Create(create_params);
   }
 
   return contents;
 }
 
 }  // namespace views