Enable posting a message from JS to Android webview.

android_webview/native/aw_message_port_service_impl.h

+// 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.
+
+#ifndef ANDROID_WEBVIEW_NATIVE_AW_MESSAGE_PORT_SERVICE_IMPL_H_
+#define ANDROID_WEBVIEW_NATIVE_AW_MESSAGE_PORT_SERVICE_IMPL_H_
+
+#include <jni.h>
+#include <map>
+
+#include "android_webview/browser/aw_message_port_service.h"
+#include "base/android/jni_weak_ref.h"
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/strings/string16.h"
+
+namespace android_webview {
+
+// This class is the native peer of AwMessagePortService.java. Please see the
+// java class for an explanation of use, ownership and lifetime.

[mnaganov (inactive), 2015/01/07 11:43:54]

I would recommend adding comments and asserts about threading assumptions, as
this object is intended to be used on IO thread.

[sgurun-gerrit only, 2015/01/10 02:36:29]

Done.

+class AwMessagePortServiceImpl : public AwMessagePortService {
+ public:
+  static AwMessagePortServiceImpl* GetInstance();
+
+  AwMessagePortServiceImpl();
+  ~AwMessagePortServiceImpl();
+  void Init(JNIEnv* env, jobject object);
+
+  void OnMessageChannelCreated(
+      AwMessagePortMessageFilter* filter,
+      base::android::ScopedJavaGlobalRef<jobject>* callback,
+      int* port1,
+      int* port2);
+
+  // AwMessagePortService implementation
+  void OnConvertedMessage(
+      int message_port_id,
+      const base::ListValue& message,
+      const std::vector<int>& sent_message_port_ids) override;
+  void OnMessagePortMessageFilterClosing(
+      AwMessagePortMessageFilter* filter) override;
+
+private:
+  void AddPort(int message_port_id, AwMessagePortMessageFilter* filter);
+
+  JavaObjectWeakGlobalRef java_ref_;
+  typedef std::map<int, AwMessagePortMessageFilter*> MessagePorts;
+  MessagePorts ports_;
+
+  DISALLOW_COPY_AND_ASSIGN(AwMessagePortServiceImpl);
+};
+
+bool RegisterAwMessagePortService(JNIEnv* env);
+
+}  // namespace android_webview
+
+#endif  // ANDROID_WEBVIEW_NATIVE_AW_MESSAGE_PORT_SERVICE_IMPL_H_