Remove old getter/setter for SigninErrorProvider.

ios/public/provider/chrome/browser/signin/signin_error_provider.h

 // Copyright 2015 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 IOS_PUBLIC_PROVIDER_CHROME_BROWSER_SIGNIN_SIGNIN_ERROR_PROVIDER_H_
 #define IOS_PUBLIC_PROVIDER_CHROME_BROWSER_SIGNIN_SIGNIN_ERROR_PROVIDER_H_
 
 #include "base/macros.h"
 
 @class NSError;
@@ skipping 13 matching lines @@
   NETWORK_ERROR,           // Should be treated as transient/offline errors.
   USER_CANCELLATION_ERROR  // Should be treated as a no-op.
 };
 
 enum class SigninError {
   CANCELED,           // Operation canceled.
   MISSING_IDENTITY,   // Request is missing identity.
   HANDLED_INTERNALLY  // Has been displayed to the user already.
 };
 
-// Registers and returns the global SigninErrorProvider.
-void SetSigninErrorProvider(SigninErrorProvider* provider);
-SigninErrorProvider* GetSigninErrorProvider();
-
 // Provides utility methods and constants for interpreting signin errors.
 class SigninErrorProvider {
  public:
   SigninErrorProvider();
   virtual ~SigninErrorProvider();
 
   // Returns what family an error belongs to.
   virtual SigninErrorCategory GetErrorCategory(NSError* error);
 
   // Tests if an NSError is user cancellation error.
@@ skipping 15 matching lines @@
   // Gets the error code corresponding to |error|.
   virtual int GetCode(SigninError error);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SigninErrorProvider);
 };
 
 }  // namespace ios
 
 #endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_SIGNIN_SIGNIN_ERROR_PROVIDER_H_