Signin/OAuth: Create an AccessTokenFetcher helper class

components/signin/core/browser/fake_signin_manager.cc

Index: components/signin/core/browser/fake_signin_manager.cc
diff --git a/components/signin/core/browser/fake_signin_manager.cc b/components/signin/core/browser/fake_signin_manager.cc
index 32caba99d7b1cd971caa67de4050628d9902a39d..11af624ff4e55c381f823fb384c965ab23816033 100644
--- a/components/signin/core/browser/fake_signin_manager.cc
+++ b/components/signin/core/browser/fake_signin_manager.cc
@@ -13,11 +13,21 @@
 FakeSigninManagerBase::FakeSigninManagerBase(
     SigninClient* client,
     AccountTrackerService* account_tracker_service)
-    : SigninManagerBase(client, account_tracker_service) {}
+    : SigninManagerBase(client, account_tracker_service),
+      auth_in_progress_(false) {}
 
 FakeSigninManagerBase::~FakeSigninManagerBase() {}
 
+bool FakeSigninManagerBase::AuthInProgress() const {
+  return auth_in_progress_;
+}
+
+void FakeSigninManagerBase::SetAuthInProgress(bool auth_in_progress) {
+  auth_in_progress_ = auth_in_progress;
+}
+
 void FakeSigninManagerBase::SignIn(const std::string& account_id) {
+  auth_in_progress_ = false;
   SetAuthenticatedAccountId(account_id);
 }