Move SigninTracker away from listening for SigninManager notifications

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 7395cda15cde1192a01d7a84f254f01bdeff3d67..1b475b9d56c4c6853c7a81ee5f4a958602f34e25 100644
--- a/chrome/browser/signin/fake_signin_manager.cc
+++ b/chrome/browser/signin/fake_signin_manager.cc
@@ -74,6 +74,10 @@ void FakeSigninManager::SignIn(const std::string& username,
   CompletePendingSignin();
 }
 
+void FakeSigninManager::FailSignin(const GoogleServiceAuthError& error) {
+  FOR_EACH_OBSERVER(Observer, observer_list_, GoogleSigninFailed(error));
+}
+
 void FakeSigninManager::SignOut() {
   if (IsSignoutProhibited())
     return;