Add support for faster, more limited accessibility modes.

content/renderer/accessibility/render_accessibility_impl.h

 // 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.
 
 #ifndef CONTENT_RENDERER_ACCESSIBILITY_RENDER_ACCESSIBILITY_IMPL_H_
 #define CONTENT_RENDERER_ACCESSIBILITY_RENDER_ACCESSIBILITY_IMPL_H_
 
 #include <vector>
 
 #include "base/containers/hash_tables.h"
@@ skipping 47 matching lines @@
 class CONTENT_EXPORT RenderAccessibilityImpl
     : public RenderAccessibility,
              RenderFrameObserver {
  public:
   // Request a one-time snapshot of the accessibility tree without
   // enabling accessibility if it wasn't already enabled.
   static void SnapshotAccessibilityTree(
       RenderFrameImpl* render_frame,
       AXContentTreeUpdate* response);
 
-  explicit RenderAccessibilityImpl(RenderFrameImpl* render_frame);
+  RenderAccessibilityImpl(RenderFrameImpl* render_frame,
+                          AccessibilityMode mode);
   ~RenderAccessibilityImpl() override;
 
   // RenderAccessibility implementation.
   int GenerateAXID() override;
   void SetPluginTreeSource(PluginAXTreeSource* source) override;
   void OnPluginRootNodeUpdated() override;
 
   // RenderFrameObserver implementation.
   bool OnMessageReceived(const IPC::Message& message) override;
 
@@ skipping 94 matching lines @@
 
   // So we can queue up tasks to be executed later.
   base::WeakPtrFactory<RenderAccessibilityImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderAccessibilityImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_ACCESSIBILITY_RENDERER_ACCESSIBILITY_H_