Add a content API for postMessage

content/common/view_messages.h

 // 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.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/memory/shared_memory.h"
 #include "base/process/process.h"
 #include "base/strings/string16.h"
@@ skipping 467 matching lines @@
   IPC_STRUCT_MEMBER(int32, next_page_id)
 
   // 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)
+  // Whether the data format is supplied as serialized script value, or as
+  // a simple string. If it is a raw string, we convert from string to a
+  // WebSerializedScriptValue in renderer.
+  IPC_STRUCT_MEMBER(bool, is_data_raw_string)
   // The serialized script value.
   IPC_STRUCT_MEMBER(base::string16, data)
 
   // When sent to the browser, this is the routing ID of the source frame in
   // the source process.  The browser replaces it with the routing ID of the
   // equivalent (swapped out) frame in the destination process.
   IPC_STRUCT_MEMBER(int, source_routing_id)
 
   // The origin of the source frame.
   IPC_STRUCT_MEMBER(base::string16, source_origin)
@@ skipping 1200 matching lines @@
 // Since the browser keeps handles to the allocated transport DIBs, this
 // message is sent to tell the browser that it may release them when the
 // renderer is finished with them.
 IPC_MESSAGE_CONTROL1(ViewHostMsg_FreeTransportDIB,
                      TransportDIB::Id /* DIB id */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent ViewMsg, then ifdefs for platform specific ViewMsg, then platform
 // independent ViewHostMsg, then ifdefs for platform specific ViewHostMsg.