Add support for faster, more limited accessibility modes.

content/renderer/accessibility/blink_ax_tree_source.h

 // Copyright 2014 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_BLINK_AX_TREE_SOURCE_H_
 #define CONTENT_RENDERER_ACCESSIBILITY_BLINK_AX_TREE_SOURCE_H_
 
 #include <stdint.h>
 
+#include "content/common/accessibility_mode_enums.h"
 #include "content/common/ax_content_node_data.h"
 #include "third_party/WebKit/public/web/WebAXObject.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/accessibility/ax_tree_source.h"
 
 namespace content {
 
 class BlinkAXTreeSource;
 class RenderFrameImpl;
 
 // Create this on the stack to freeze BlinkAXTreeSource and automatically
 // un-freeze it when it goes out of scope.
 class ScopedFreezeBlinkAXTreeSource {
  public:
   explicit ScopedFreezeBlinkAXTreeSource(BlinkAXTreeSource* tree_source);
   ~ScopedFreezeBlinkAXTreeSource();
 
  private:
   BlinkAXTreeSource* tree_source_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedFreezeBlinkAXTreeSource);
 };
 
 class BlinkAXTreeSource
     : public ui::AXTreeSource<blink::WebAXObject,
                               AXContentNodeData,
                               AXContentTreeData> {
  public:
-  BlinkAXTreeSource(RenderFrameImpl* render_frame);
+  BlinkAXTreeSource(RenderFrameImpl* render_frame,
+                    AccessibilityMode mode);
   ~BlinkAXTreeSource() override;
 
   // Freeze caches the document, accessibility root, and current focused
   // object for fast retrieval during a batch of operations. Use
   // ScopedFreezeBlinkAXTreeSource on the stack rather than calling
   // these directly.
   void Freeze();
   void Thaw();
 
   // It may be necessary to call SetRoot if you're using a WebScopedAXContext,
@@ skipping 51 matching lines @@
   }
   const blink::WebAXObject& focus() const {
     DCHECK(frozen_);
     return focus_;
   }
 
   blink::WebAXObject ComputeRoot() const;
 
   RenderFrameImpl* render_frame_;
 
+  AccessibilityMode accessibility_mode_;
+
   // An explicit root to use, otherwise it's taken from the WebDocument.
   blink::WebAXObject explicit_root_;
 
   // The id of the object with accessibility focus.
   int accessibility_focus_id_ = -1;
 
   // The id of the object to fetch image data for.
   int image_data_node_id_ = -1;
 
   gfx::Size max_image_data_size_;
 
   // These are updated when calling |Freeze|.
   bool frozen_ = false;
   blink::WebDocument document_;
   blink::WebAXObject root_;
   blink::WebAXObject focus_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_ACCESSIBILITY_BLINK_AX_TREE_SOURCE_H_