Remove references to IsNewAvatarMenu since the flag was removed.

components/signin/core/common/signin_switches.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 COMPONENTS_SIGNIN_CORE_COMMON_SIGNIN_SWITCHES_H_
 #define COMPONENTS_SIGNIN_CORE_COMMON_SIGNIN_SWITCHES_H_
 
 namespace switches {
 
 // These switches should not be queried from CommandLine::HasSwitch() directly.
 // Always go through the helper functions in profile_management_switches.h
 // to properly take into account the state of field trials.
 
 // All switches in alphabetical order. The switches should be documented
 // alongside the definition of their values in the .cc file.
 extern const char kClearTokenService[];
 extern const char kDisableAccountConsistency[];
-extern const char kDisableNewAvatarMenu[];
 extern const char kDisableNewProfileManagement[];
 extern const char kDisableSigninScopedDeviceId[];
 extern const char kEnableAccountConsistency[];
 extern const char kEnableIframeBasedSignin[];
-extern const char kEnableNewAvatarMenu[];
 extern const char kEnableNewProfileManagement[];
 extern const char kEnableRefreshTokenAnnotationRequest[];
 extern const char kExtensionsMultiAccount[];
 extern const char kGoogleProfileInfo[];
 
 }  // namespace switches
 
 #endif  // COMPONENTS_SIGNIN_CORE_COMMON_SIGNIN_SWITCHES_H_