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

content/browser/accessibility/cross_platform_accessibility_browsertest.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 <string>
 #include <vector>
 
 #include "base/utf_string_conversions.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/common/accessibility_mode.h"
 #include "content/public/test/test_utils.h"
 #include "content/test/content_browser_test.h"
 #include "content/test/content_browser_test_utils.h"
 #include "content/shell/shell.h"
 
 #if defined(OS_WIN)
 #include <atlbase.h>
 #include <atlcom.h>
 #include "base/win/scoped_com_initializer.h"
 #include "ui/base/win/atl_module.h"
@@ skipping 434 matching lines @@
   const AccessibilityNodeData& tree = GetAccessibilityNodeDataTree();
 
   ASSERT_EQ(1U, tree.children.size());
   const AccessibilityNodeData& textbox = tree.children[0];
 
   EXPECT_EQ(
       true, GetBoolAttr(textbox, AccessibilityNodeData::ATTR_CAN_SET_VALUE));
 }
 
 }  // namespace content