Move some accessibility methods, enums and interfaces into the content/public API.

content/public/browser/accessibility_tree_formatter.h

Index: content/public/browser/accessibility_tree_formatter.h
diff --git a/content/public/browser/accessibility_tree_formatter.h b/content/public/browser/accessibility_tree_formatter.h
new file mode 100644
index 0000000000000000000000000000000000000000..6e50923c42a8a7688f44584f3c98b1c417ed3f5e
--- /dev/null
+++ b/content/public/browser/accessibility_tree_formatter.h
@@ -0,0 +1,27 @@
+// Copyright (c) 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_PUBLIC_BROWSER_ACCESSIBILITY_TREE_FORMATTER_H_
+#define CONTENT_PUBLIC_BROWSER_ACCESSIBILITY_TREE_FORMATTER_H_
+
+#include "base/string16.h"
+
+namespace content {
+
+class RenderViewHost;
+
+class AccessibilityTreeFormatter {
+ public:
+  virtual ~AccessibilityTreeFormatter() {}
+
+  static AccessibilityTreeFormatter* Create(RenderViewHost* rvh);
+
+  // Formats the browser accessibility tree for this render view host into
+  // a string.
+  virtual void FormatAccessibilityTree(string16* contents) = 0;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_ACCESSIBILITY_TREE_FORMATTER_H_