Implementation of the "Redirect URLs to Packaged Apps" feature.

content/browser/renderer_host/extension_system_message_filter.h

Index: content/browser/renderer_host/extension_system_message_filter.h
diff --git a/content/browser/renderer_host/extension_system_message_filter.h b/content/browser/renderer_host/extension_system_message_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..e4e4964014052ba65a7a13f10bd75470ec02c27e
--- /dev/null
+++ b/content/browser/renderer_host/extension_system_message_filter.h
@@ -0,0 +1,49 @@
+// Copyright (c) 2013 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 CONTENT_RENDERER_EXTENSION_SYSTEM_MESSAGE_FILTER_H_
+#define CONTENT_RENDERER_EXTENSION_SYSTEM_MESSAGE_FILTER_H_
+
+#include <string>
+
+#include "content/public/browser/browser_message_filter.h"
+
+class GURL;
+
+namespace content {
+
+class RenderProcessHost;
+
+// This class filters out incoming IPC messages for the extension system on the
+// browser IPC thread.
+class ExtensionSystemMessageFilter : public BrowserMessageFilter {

[Charlie Reis, 2013/08/26 22:17:52]

Extensions are a chrome/ concept and don't belong in content/.

[sergeygs, 2013/08/29 08:24:42]

I think it's purely about naming: I've just been overly specific about what's
going on here on the renderer's and renderer host's side. What's actually
happening is:
- The renderer essentially asks ChromeContentRendererClient, which plays a role
of the browser's representative on the renderer's side, whether the browser
could handle the URL. The renderer doesn't need to know what "could handle"
really mean (in reality it means that the browser has a registered app that can
handle the URL).
- If ChromeContentRendererClient thinks so, it tells the renderer back to stop
navigating to the URL, and sends an IPC message to the renderer host which
essentially tells the host to forward the URL to the browser for handling.
- The renderer does so by sending a notification through the
NotificationService.
- The browser receives the notification and only then this gets again
reinterpreted as a command to launch an app.
So on the renderer side it's all about URL forwarding to the browser. I've
changed the naming of classes and files accordingly, so I hope it looks good
now.

On 2013/08/26 22:17:52, creis wrote:

+ public:
+  // Create the filter.
+  ExtensionSystemMessageFilter(RenderProcessHost* render_process_host);
+
+  // BrowserMessageFilter methods:
+  virtual bool OnMessageReceived(const IPC::Message& message,
+                                 bool* message_was_ok) OVERRIDE;
+
+  //OnMessageReceive sends notifications to ExtensionSystem through
+  // NotificationService: to reach the target, these need to be on the UI
+  // thread, so we need to override.
+  virtual void OverrideThreadForMessage(
+      const IPC::Message& message,
+      content::BrowserThread::ID* thread) OVERRIDE;
+
+ private:
+  virtual ~ExtensionSystemMessageFilter();
+
+  bool OnLaunchAppWithUrl(const std::string& app_id,
+                          const std::string& handler_id,
+                          const GURL& url,
+                          const GURL& referrer_url);
+
+  RenderProcessHost* render_process_host_;
+};
+
+}
+
+#endif // CONTENT_RENDERER_EXTENSION_SYSTEM_MESSAGE_FILTER_H_