Add a content API to create a message channel.

content/browser/message_port_provider.cc

Index: content/browser/message_port_provider.cc
diff --git a/content/browser/message_port_provider.cc b/content/browser/message_port_provider.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d00fdf1328617f5f9b88b0654f3de4839cfb371e
--- /dev/null
+++ b/content/browser/message_port_provider.cc
@@ -0,0 +1,68 @@
+// Copyright 2014 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 "content/public/browser/message_port_provider.h"
+
+#include "base/basictypes.h"
+#include "content/browser/browser_thread_impl.h"
+#include "content/browser/message_port_message_filter.h"
+#include "content/browser/message_port_service.h"
+#include "content/browser/renderer_host/render_process_host_impl.h"
+#include "content/browser/renderer_host/render_view_host_impl.h"
+#include "content/browser/web_contents/web_contents_impl.h"
+#include "content/common/view_messages.h"
+
+namespace content {
+
+void MessagePortProvider::PostMessageToFrame(
+    WebContents* web_contents,
+    const base::string16& source_origin,
+    const base::string16& target_origin,
+    const base::string16& data,
+    const std::vector<int>& ports) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  RenderViewHost* rvh = web_contents->GetRenderViewHost();
+  if (!rvh)
+    return;
+
+  ViewMsg_PostMessage_Params params;
+  params.is_data_raw_string = true;
+  params.data = data;
+  params.source_routing_id = web_contents->GetRoutingID();
+  params.source_origin = source_origin;
+  params.target_origin = target_origin;
+  RenderProcessHostImpl* rph =
+      static_cast<RenderProcessHostImpl*>(
+          web_contents->GetRenderProcessHost());
+  MessagePortMessageFilter* mf = rph->message_port_message_filter();
+
+  if (!ports.empty()) {
+    params.message_port_ids = ports;
+    mf->UpdateMessagePortsWithNewRoutes(params.message_port_ids,
+                                        &params.new_routing_ids);
+  }
+  rvh->Send(new ViewMsg_PostMessageEvent(
+                web_contents->GetRenderViewHost()->GetRoutingID(),
+                params));
+}
+
+void MessagePortProvider::CreateMessageChannel(WebContents* web_contents,
+                                               int* port1,
+                                               int* port2) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  *port1 = 0;
+  *port2 = 0;
+
+  RenderProcessHostImpl* rph =
+      static_cast<RenderProcessHostImpl*>(
+          web_contents->GetRenderProcessHost());
+  MessagePortMessageFilter* mf = rph->message_port_message_filter();
+  MessagePortService* msp = MessagePortService::GetInstance();
+  msp->Create(mf->GetNextRoutingID(), mf, port1);
+  msp->Create(mf->GetNextRoutingID(), mf, port2);
+}
+
+} // namespace content