[Clean-up] Remove some dead code for handling Webstore sign-in.

components/signin/core/browser/signin_manager.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.
 //
 // The signin manager encapsulates some functionality tracking
 // which user is signed in. See SigninManagerBase for full description of
 // responsibilities. The class defined in this file provides functionality
 // required by all platforms except Chrome OS.
 //
 // When a user is signed in, a ClientLogin request is run on their behalf.
@@ skipping 112 matching lines @@
 
   // Tells the SigninManager whether to prohibit signout for this profile.
   // If |prohibit_signout| is true, then signout will be prohibited.
   void ProhibitSignout(bool prohibit_signout);
 
   // If true, signout is prohibited for this profile (calls to SignOut() are
   // ignored).
   bool IsSignoutProhibited() const;
 
   // Add or remove observers for the merge session notification.
-  virtual void AddMergeSessionObserver(
-      MergeSessionHelper::Observer* observer);
-  virtual void RemoveMergeSessionObserver(
-      MergeSessionHelper::Observer* observer);
+  void AddMergeSessionObserver(MergeSessionHelper::Observer* observer);
+  void RemoveMergeSessionObserver(MergeSessionHelper::Observer* observer);
 
  protected:
   // Flag saying whether signing out is allowed.
   bool prohibit_signout_;
 
  private:
   enum SigninType { SIGNIN_TYPE_NONE, SIGNIN_TYPE_WITH_REFRESH_TOKEN };
 
   std::string SigninTypeToString(SigninType type);
   friend class FakeSigninManager;
@@ skipping 65 matching lines @@
   scoped_ptr<MergeSessionHelper> merge_session_helper_;
 
   base::WeakPtrFactory<SigninManager> weak_pointer_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SigninManager);
 };
 
 #endif  // !defined(OS_CHROMEOS)
 
 #endif  // COMPONENTS_SIGNIN_CORE_BROWSER_SIGNIN_MANAGER_H_