Add an extension bubble explaining which extensions are in dev mode.

chrome/browser/extensions/dev_mode_bubble_controller.h

Index: chrome/browser/extensions/dev_mode_bubble_controller.h
diff --git a/chrome/browser/extensions/dev_mode_bubble_controller.h b/chrome/browser/extensions/dev_mode_bubble_controller.h
new file mode 100644
index 0000000000000000000000000000000000000000..65a320fb0fc3070b252f78335bfdf8509b09b4d3
--- /dev/null
+++ b/chrome/browser/extensions/dev_mode_bubble_controller.h
@@ -0,0 +1,59 @@
+// 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 CHROME_BROWSER_EXTENSIONS_DEV_MODE_BUBBLE_CONTROLLER_H_
+#define CHROME_BROWSER_EXTENSIONS_DEV_MODE_BUBBLE_CONTROLLER_H_
+
+#include <string>
+#include "chrome/browser/extensions/api/profile_keyed_api_factory.h"
+#include "chrome/browser/extensions/extension_message_bubble_controller.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+#include "extensions/common/extension.h"
+
+class Browser;
+class ExtensionService;
+
+namespace extensions {
+
+class DevModeBubble;
+
+class DevModeBubbleController
+    : public ProfileKeyedAPI,
+      public ExtensionMessageBubbleController {
+ public:
+  explicit DevModeBubbleController(Profile* profile);
+  virtual ~DevModeBubbleController();
+
+  // ProfileKeyedAPI implementation.
+  static ProfileKeyedAPIFactory<DevModeBubbleController>* GetFactoryInstance();
+
+  // Convenience method to get the DevModeBubbleController for a
+  // profile.
+  static DevModeBubbleController* Get(Profile* profile);
+
+ private:
+  friend class ProfileKeyedAPIFactory<DevModeBubbleController>;
+
+  // ProfileKeyedAPI implementation.
+  static const char* service_name() {
+    return "DevModeBubbleController";
+  }
+  static const bool kServiceRedirectedInIncognito = true;
+
+  // ExtensionMessageBubbleController methods.
+  virtual bool ShouldIncludeExtension(const std::string& extension_id) OVERRIDE;
+  virtual void AcknowledgeExtension(const std::string& extension_id) OVERRIDE;
+  virtual void PerformAction() OVERRIDE;
+
+  DISALLOW_COPY_AND_ASSIGN(DevModeBubbleController);
+};
+
+template <>
+void ProfileKeyedAPIFactory<
+    DevModeBubbleController>::DeclareFactoryDependencies();
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_DEV_MODE_BUBBLE_CONTROLLER_H_