Make extensions developer mode warning controllable by experiments

chrome/browser/extensions/dev_mode_bubble_controller.h

 // 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/extension_message_bubble_controller.h"
 
 namespace extensions {
 
 class Extension;
 
 class DevModeBubbleController : public ExtensionMessageBubbleController {
  public:
   // Clears the list of profiles the bubble has been shown for. Should only be
   // used during testing.
   static void ClearProfileListForTesting();
 
-  // Returns true if the extension is considered a Developer Mode extension.
-  static bool IsDevModeExtension(const Extension* extension);
-
   explicit DevModeBubbleController(Profile* profile);
   ~DevModeBubbleController() override;
 
   // Whether the controller knows of extensions to list in the bubble. Returns
   // true if so.
   bool ShouldShow();
 
   // ExtensionMessageBubbleController methods.
   void Show(ExtensionMessageBubble* bubble) override;
 
  private:
   // A weak pointer to the profile we are associated with. Not owned by us.
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(DevModeBubbleController);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_DEV_MODE_BUBBLE_CONTROLLER_H_