Revert of Migrate accessibility from RenderView to RenderFrame.

content/common/view_messages.h

Index: content/common/view_messages.h
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index e55e51e47244f2c91587ba0c2b0095a021c0ed43..f4a765adc57bb957ab5f723ac6e627be46e87101 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -68,6 +68,7 @@
 
 #define IPC_MESSAGE_START ViewMsgStart
 
+IPC_ENUM_TRAITS(AccessibilityMode)
 IPC_ENUM_TRAITS(blink::WebMediaPlayerAction::Type)
 IPC_ENUM_TRAITS(blink::WebPluginAction::Type)
 IPC_ENUM_TRAITS(blink::WebPopupType)
@@ -478,6 +479,9 @@
 
   // The properties of the screen associated with the view.
   IPC_STRUCT_MEMBER(blink::WebScreenInfo, screen_info)
+
+  // The accessibility mode of the renderer.
+  IPC_STRUCT_MEMBER(AccessibilityMode, accessibility_mode)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(ViewMsg_PostMessage_Params)
@@ -864,6 +868,10 @@
 // Temporary message to diagnose an unexpected condition in WebContentsImpl.
 IPC_MESSAGE_CONTROL1(ViewMsg_TempCrashWithData,
                      GURL /* data */)
+
+// Change the accessibility mode in the renderer process.
+IPC_MESSAGE_ROUTED1(ViewMsg_SetAccessibilityMode,
+                    AccessibilityMode)
 
 // An acknowledge to ViewHostMsg_MultipleTargetsTouched to notify the renderer
 // process to release the magnified image.