[signin] Add DICe flow for account consistency requests.

components/signin/core/common/profile_management_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.
 
 // These are functions to access various profile-management flags but with
 // possible overrides from Experiements.  This is done inside chrome/common
 // because it is accessed by files through the chrome/ directory tree.
 
 #ifndef COMPONENTS_SIGNIN_CORE_COMMON_PROFILE_MANAGEMENT_SWITCHES_H_
 #define COMPONENTS_SIGNIN_CORE_COMMON_PROFILE_MANAGEMENT_SWITCHES_H_
 
+#include "build/build_config.h"
+
 namespace base {
 class CommandLine;
 }
 
 namespace switches {
 
+enum class AccountConsistencyMethod {
+  kDisabled,  // No account consistency.
+  kMirror,    // Account management UI in the avatar bubble.
+  kDice       // Account management UI on Gaia webpages.
+};
+
+// Returns the account consistency method.
+AccountConsistencyMethod GetAccountConsistencyMethod();
+
 // Checks whether Mirror account consistency is enabled. If enabled, the account
 // management UI is available in the avatar bubble.
+// DEPRECATED: Use GetAccountConsistencyMethod() instead.
 bool IsAccountConsistencyMirrorEnabled();
 
 // Whether the chrome.identity API should be multi-account.
 bool IsExtensionsMultiAccount();
 
 // Called in tests to force enable Mirror account consistency.
 void EnableAccountConsistencyMirrorForTesting(base::CommandLine* command_line);
 
+// Dice is only supported on desktop.
+#if !defined(OS_ANDROID) && !defined(OS_IOS)
+// Called in tests to force enable Dice account consistency.
+void EnableAccountConsistencyDiceForTesting(base::CommandLine* command_line);
+#endif
+
 }  // namespace switches
 
 #endif  // COMPONENTS_SIGNIN_CORE_COMMON_PROFILE_MANAGEMENT_SWITCHES_H_