[Extensions] Clean up MessagingBindings

extensions/renderer/messaging_bindings.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 EXTENSIONS_RENDERER_MESSAGING_BINDINGS_H_
 #define EXTENSIONS_RENDERER_MESSAGING_BINDINGS_H_
 
 #include <string>
 
-#include "extensions/renderer/script_context_set.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "extensions/renderer/object_backed_native_handler.h"
 
 struct ExtensionMsg_ExternalConnectionInfo;
 struct ExtensionMsg_TabConnectionInfo;
 
-namespace base {
-class DictionaryValue;
-}
-
 namespace content {
 class RenderFrame;
 }
 
-namespace v8 {
-class Extension;
-}
-
 namespace extensions {
 struct Message;
-class ObjectBackedNativeHandler;
 class ScriptContextSet;
 
 // Manually implements JavaScript bindings for extension messaging.
-//
-// TODO(aa): This should all get re-implemented using SchemaGeneratedBindings.
-// If anything needs to be manual for some reason, it should be implemented in
-// its own class.
-class MessagingBindings {
+class MessagingBindings : public ObjectBackedNativeHandler {
  public:
-  // Creates an instance of the extension.
-  static ObjectBackedNativeHandler* Get(ScriptContext* context);
+  explicit MessagingBindings(ScriptContext* script_context);
+  ~MessagingBindings() override;
 
   // Checks whether the port exists in the given frame. If it does not, a reply
   // is sent back to the browser.
   static void ValidateMessagePort(const ScriptContextSet& context_set,
                                   int port_id,
                                   content::RenderFrame* render_frame);
 
   // Dispatches the onConnect content script messaging event to some contexts
   // in |context_set|. If |restrict_to_render_frame| is specified, only contexts
   // in that render frame will receive the message.
@@ skipping 12 matching lines @@
                              int target_port_id,
                              const Message& message,
                              content::RenderFrame* restrict_to_render_frame);
 
   // Dispatches the onDisconnect event in response to the channel being closed.
   static void DispatchOnDisconnect(
       const ScriptContextSet& context_set,
       int port_id,
       const std::string& error_message,
       content::RenderFrame* restrict_to_render_frame);
+
+ private:
+  // JS Exposed Function: Sends a message along the given channel.
+  void PostMessage(const v8::FunctionCallbackInfo<v8::Value>& args);
+
+  // JS Exposed Function: Close a port, optionally forcefully (i.e. close the
+  // whole channel instead of just the given port).
+  void CloseChannel(const v8::FunctionCallbackInfo<v8::Value>& args);
+
+  // JS Exposed Function: Binds |callback| to be invoked *sometime after*
+  // |object| is garbage collected. We don't call the method re-entrantly so as
+  // to avoid executing JS in some bizarro undefined mid-GC state, nor do we
+  // then call into the script context if it's been invalidated.
+  void BindToGC(const v8::FunctionCallbackInfo<v8::Value>& args);
+
+  // Helper function to close a port. See CloseChannel() for |force_close|
+  // documentation.
+  void ClosePort(int port_id, bool force_close);
+
+  base::WeakPtrFactory<MessagingBindings> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(MessagingBindings);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_MESSAGING_BINDINGS_H_