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

chrome/browser/signin/fake_signin_manager.cc

Index: chrome/browser/signin/fake_signin_manager.cc
diff --git a/chrome/browser/signin/fake_signin_manager.cc b/chrome/browser/signin/fake_signin_manager.cc
index 555df846add54ca0c820c3a1e7c2def48895e665..0bc6d702e8bd1051863abdaeca9f4e6ea087d071 100644
--- a/chrome/browser/signin/fake_signin_manager.cc
+++ b/chrome/browser/signin/fake_signin_manager.cc
@@ -68,24 +68,6 @@ void FakeSigninManager::CompletePendingSignin() {
                                           password_));
 }
 
-void FakeSigninManager::AddMergeSessionObserver(
-    MergeSessionHelper::Observer* observer) {
-  SigninManager::AddMergeSessionObserver(observer);
-  merge_session_observer_list_.AddObserver(observer);
-}
-
-void FakeSigninManager::RemoveMergeSessionObserver(
-    MergeSessionHelper::Observer* observer) {
-  SigninManager::RemoveMergeSessionObserver(observer);
-  merge_session_observer_list_.RemoveObserver(observer);
-}
-
-void FakeSigninManager::NotifyMergeSessionObservers(
-    const GoogleServiceAuthError& error) {
-  FOR_EACH_OBSERVER(MergeSessionHelper::Observer, merge_session_observer_list_,
-                    MergeSessionCompleted(GetAuthenticatedUsername(), error));
-}
-
 void FakeSigninManager::SignIn(const std::string& username,
                                const std::string& password) {
   StartSignInWithRefreshToken(