Avoid enabling accessibility for WebContents that are never shown

content/browser/frame_host/render_frame_host_impl.h

 // Copyright 2013 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 CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_IMPL_H_
 #define CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 424 matching lines @@
   // selection.
   void DeleteSurroundingText(size_t before, size_t after);
 
   // Notifies the RenderFrame that the JavaScript message that was shown was
   // closed by the user.
   void JavaScriptDialogClosed(IPC::Message* reply_msg,
                               bool success,
                               const base::string16& user_input,
                               bool dialog_was_suppressed);
 
-  // Send a message to the renderer process to change the accessibility mode.
-  void SetAccessibilityMode(AccessibilityMode AccessibilityMode);
+  // Get the accessibility mode from the delegate and Send a message to the
+  // renderer process to change the accessibility mode.
+  void UpdateAccessibilityMode();
 
   // Request a one-time snapshot of the accessibility tree without changing
   // the accessibility mode.
   void RequestAXTreeSnapshot(AXTreeSnapshotCallback callback);
 
   // Resets the accessibility serializer in the renderer.
   void AccessibilityReset();
 
   // Turn on accessibility testing. The given callback will be run
   // every time an accessibility notification is received from the
@@ skipping 614 matching lines @@
       remote_associated_interfaces_;
   // NOTE: This must be the last member.
   base::WeakPtrFactory<RenderFrameHostImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_IMPL_H_