Refactor AO2TS to make it easier to componentize.

components/signin/core/browser/profile_oauth2_token_service.cc

 // 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.
 
 #include "components/signin/core/browser/profile_oauth2_token_service.h"
 
-#include "base/bind.h"
-#include "base/message_loop/message_loop.h"
-#include "base/stl_util.h"
-#include "base/time/time.h"
-#include "components/signin/core/browser/signin_client.h"
-#include "components/signin/core/browser/signin_error_controller.h"
-#include "google_apis/gaia/gaia_auth_util.h"
+#include "google_apis/gaia/oauth2_token_service_delegate.h"
 #include "net/url_request/url_request_context_getter.h"
 
-ProfileOAuth2TokenService::ProfileOAuth2TokenService()
-    : client_(NULL),
-      signin_error_controller_(NULL) {}
+ProfileOAuth2TokenService::ProfileOAuth2TokenService(
+    OAuth2TokenServiceDelegate* delegate)
+    : OAuth2TokenService(delegate) {
+}
 
 ProfileOAuth2TokenService::~ProfileOAuth2TokenService() {}
 
-void ProfileOAuth2TokenService::Initialize(
-    SigninClient* client,
-    SigninErrorController* signin_error_controller) {
-  DCHECK(client);
-  DCHECK(!client_);
-  DCHECK(signin_error_controller);
-  DCHECK(!signin_error_controller_);
-  client_ = client;
-  signin_error_controller_ = signin_error_controller;
-}
-
 void ProfileOAuth2TokenService::Shutdown() {
-  DCHECK(client_) << "Shutdown() called without matching call to Initialize()";
-}
-
-net::URLRequestContextGetter* ProfileOAuth2TokenService::GetRequestContext() {
-  return NULL;
-}
-
-void ProfileOAuth2TokenService::UpdateAuthError(
-    const std::string& account_id,
-    const GoogleServiceAuthError& error) {
-  NOTREACHED();
-}
-
-void ProfileOAuth2TokenService::ValidateAccountId(
-    const std::string& account_id) const {
-  DCHECK(!account_id.empty());
-
-  // If the account is given as an email, make sure its a canonical email.
-  // Note that some tests don't use email strings as account id, and after
-  // the gaia id migration it won't be an email.  So only check for
-  // canonicalization if the account_id is suspected to be an email.
-  if (account_id.find('@') != std::string::npos)
-    DCHECK_EQ(gaia::CanonicalizeEmail(account_id), account_id);
-}
-
-std::vector<std::string> ProfileOAuth2TokenService::GetAccounts() {
-  NOTREACHED();
-  return std::vector<std::string>();
+  CancelAllRequests();
+  GetDelegate()->Shutdown();
 }
 
 void ProfileOAuth2TokenService::LoadCredentials(
     const std::string& primary_account_id) {
-  // Empty implementation by default.
+  CancelAllRequests();
+  GetDelegate()->LoadCredentials(primary_account_id);

[Roger Tawa OOO till Jul 10th, 2015/05/28 14:54:43]

Do we really need to call CancelAllRequests() on load?  The request list should
be empty as this point.

[gogerald1, 2015/06/03 18:12:58]

Done. Confirmed with chromeos guy

 }
 
 void ProfileOAuth2TokenService::UpdateCredentials(
     const std::string& account_id,
     const std::string& refresh_token) {
-  NOTREACHED();
+  std::string present_refresh_token =
+      GetDelegate()->GetRefreshToken(account_id);
+  if (!present_refresh_token.empty() &&
+      present_refresh_token == refresh_token) {
+    CancelRequestsForAccount(account_id);
+    ClearCacheForAccount(account_id);
+  }
+  GetDelegate()->UpdateCredentials(account_id, refresh_token);
 }
 
-void ProfileOAuth2TokenService::RevokeAllCredentials() {
-  // Empty implementation by default.
-}
+void ProfileOAuth2TokenService::RevokeCredentials(
+    const std::string& account_id) {
+  GetDelegate()->RevokeCredentials(account_id);
+}

[Roger Tawa OOO till Jul 10th, 2015/05/28 14:54:43]

I don't think we need these three methods in this class.  If the PO2TS added
itself as an observer of the delegate, then it would receive notifications when
refresh tokens become available.  It could then cancel requests as needed.

By doing this, you don't need the function GetRefreshToken().  The delegate
won't fire a notification unless the token actually changes in
UpdateCredentials().

[gogerald1, 2015/06/03 18:12:58]

Done.

[Roger Tawa OOO till Jul 10th, 2015/06/04 18:19:55]

You say done, but the three methods are still here.  Is there a reason for that?
 Note that for RevokeCredentials(), you could listen for On
RefreshTokenRevoked() to call CancelRequestsForAccount() and
ClearCacheForAccount().