Hack to restrict runtime API to dev channel rather than experimental.

chrome/renderer/extensions/extension_dispatcher.h

Index: chrome/renderer/extensions/extension_dispatcher.h
diff --git a/chrome/renderer/extensions/extension_dispatcher.h b/chrome/renderer/extensions/extension_dispatcher.h
index cb7f60ad15cceaa269b238fdd888c7dafee882d7..b240f3e967b8874db87bcc703a8c2c2517982c01 100644
--- a/chrome/renderer/extensions/extension_dispatcher.h
+++ b/chrome/renderer/extensions/extension_dispatcher.h
@@ -122,6 +122,7 @@ class ExtensionDispatcher : public content::RenderProcessObserver {
   virtual void WebKitInitialized() OVERRIDE;
   virtual void IdleNotification() OVERRIDE;
 
+  void OnSetChannel(int channel);
   void OnMessageInvoke(const std::string& extension_id,
                        const std::string& function_name,
                        const base::ListValue& args,
@@ -237,6 +238,9 @@ class ExtensionDispatcher : public content::RenderProcessObserver {
   // Sends API requests to the extension host.
   scoped_ptr<ExtensionRequestSender> request_sender_;
 
+  // The current channel. From VersionInfo::GetChannel().

[Yoyo Zhou, 2012/05/16 00:04:06]

Do you want to put in a TODO(aa) to remove this later too?

[Matt Perry, 2012/05/16 00:19:54]

Done.

+  int chrome_channel_;
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionDispatcher);
 };