[Extensions] Clean up renderer channel-related code

extensions/renderer/dispatcher_delegate.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_DISPATCHER_DELEGATE_H_
 #define EXTENSIONS_RENDERER_DISPATCHER_DELEGATE_H_
 
 #include <set>
 #include <string>
 
-namespace blink {
-class WebFrame;
-}
-
 namespace extensions {
 class Dispatcher;
 class Extension;
 class ModuleSystem;
 class ResourceBundleSourceMap;
 class ScriptContext;
-class URLPatternSet;
 
 // Base class and default implementation for an extensions::Dispacher delegate.
 // DispatcherDelegate can be used to override and extend the behavior of the
 // extensions system's renderer side.
 class DispatcherDelegate {
  public:
   virtual ~DispatcherDelegate() {}
 
   // Initializes origin permissions for a newly created extension context.
   virtual void InitOriginPermissions(const Extension* extension,
                                      bool is_extension_active) {}
 
   // Includes additional native handlers in a ScriptContext's ModuleSystem.
   virtual void RegisterNativeHandlers(Dispatcher* dispatcher,
                                       ModuleSystem* module_system,
                                       ScriptContext* context) {}
 
   // Includes additional source resources into the resource map.
   virtual void PopulateSourceMap(ResourceBundleSourceMap* source_map) {}
 
   // Requires additional modules within an extension context's module system.
   virtual void RequireAdditionalModules(ScriptContext* context,
                                         bool is_within_platform_app) {}
 
   // Allows the delegate to respond to an updated set of active extensions in
   // the Dispatcher.
   virtual void OnActiveExtensionsUpdated(
       const std::set<std::string>& extension_ids) {}
-
-  // Sets the current Chrome channel.
-  // TODO(rockot): This doesn't belong in a generic extensions system interface.
-  // See http://crbug.com/368431.
-  virtual void SetChannel(int channel) {}
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_DISPATCHER_DELEGATE_H_