Migrate accessibility from RenderView to RenderFrame.

content/common/frame_messages.h

Index: content/common/frame_messages.h
diff --git a/content/common/frame_messages.h b/content/common/frame_messages.h
index b9f4fb7974e8b9cba6869eaa0529855b5ee37bba..670312087cf523f83b49b9246acdfd19150368ea 100644
--- a/content/common/frame_messages.h
+++ b/content/common/frame_messages.h
@@ -25,6 +25,9 @@
 
 #define IPC_MESSAGE_START FrameMsgStart
 
+IPC_ENUM_TRAITS_MIN_MAX_VALUE(AccessibilityMode,
+                              AccessibilityModeOff,
+                              AccessibilityModeComplete)
 IPC_ENUM_TRAITS_MIN_MAX_VALUE(content::JavaScriptMessageType,
                               content::JAVASCRIPT_MESSAGE_TYPE_ALERT,
                               content::JAVASCRIPT_MESSAGE_TYPE_PROMPT)
@@ -354,6 +357,10 @@ IPC_MESSAGE_ROUTED1(FrameMsg_TextSurroundingSelectionRequest,
 // needed to support navigation transitions.
 IPC_MESSAGE_ROUTED1(FrameMsg_AddStyleSheetByURL, std::string)
 
+// Change the accessibility mode in the renderer process.
+IPC_MESSAGE_ROUTED1(FrameMsg_SetAccessibilityMode,
+                    AccessibilityMode)
+
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.