Refactor AO2TS to make it easier to componentize.

chrome/browser/chromeos/settings/device_oauth2_token_service.h

 // Copyright 2013 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_SETTINGS_DEVICE_OAUTH2_TOKEN_SERVICE_H_
 #define CHROME_BROWSER_CHROMEOS_SETTINGS_DEVICE_OAUTH2_TOKEN_SERVICE_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/stl_util.h"
 #include "base/time/time.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "google_apis/gaia/gaia_oauth_client.h"
 #include "google_apis/gaia/oauth2_token_service.h"
+#include "google_apis/gaia/oauth2_token_service_delegate.h"
 #include "net/url_request/url_request_context_getter.h"
 
 namespace gaia {
 class GaiaOAuthClient;
 }
 
 namespace net {
 class URLRequestContextGetter;
 }
 
 class PrefRegistrySimple;
 class PrefService;
 
 namespace chromeos {
 
 // DeviceOAuth2TokenService retrieves OAuth2 access tokens for a given
 // set of scopes using the device-level OAuth2 any-api refresh token
 // obtained during enterprise device enrollment.
 //
 // See |OAuth2TokenService| for usage details.
 //
 // When using DeviceOAuth2TokenService, a value of |GetRobotAccountId| should
 // be used in places where API expects |account_id|.
 //
 // Note that requests must be made from the UI thread.
 class DeviceOAuth2TokenService : public OAuth2TokenService,
                                  public gaia::GaiaOAuthClient::Delegate {
  public:
+  class DeviceOAuth2TokenServiceDelegate : public OAuth2TokenServiceDelegate {

[xiyuan, 2015/06/26 18:15:53]

nit: We can probably move DeviceOAuth2TokenServiceDelegate declartion into cc
file. See https://www.chromium.org/developers/coding-style/cpp-dos-and-donts,
look for "Move inner classes into the implementation."

Also, does this class needs to be public?

+   public:
+    friend class DeviceOAuth2TokenService;

[xiyuan, 2015/06/26 18:15:53]

Do we need this? Think inner class is friend of outer class by default.

+    DeviceOAuth2TokenServiceDelegate(
+        DeviceOAuth2TokenService* device_token_service);
+    ~DeviceOAuth2TokenServiceDelegate() override;
+
+    OAuth2AccessTokenFetcher* CreateAccessTokenFetcher(

[xiyuan, 2015/06/26 18:15:53]

nit: // OAuth2TokenServiceDelegate

+        const std::string& account_id,
+        net::URLRequestContextGetter* getter,
+        OAuth2AccessTokenConsumer* consumer) override;
+
+    bool RefreshTokenIsAvailable(const std::string& account_id) const override;
+    void UpdateAuthError(const std::string& account_id,
+                         const GoogleServiceAuthError& error) override;
+
+    std::vector<std::string> GetAccounts() override;
+    void RevokeAllCredentials() override;
+    net::URLRequestContextGetter* GetRequestContext() const override;
+
+   private:
+    DeviceOAuth2TokenService* device_token_service_;

[xiyuan, 2015/06/26 18:15:53]

nit: DISALLOW_COPY_AND_ASSIGN(...);

+  };
+
   typedef base::Callback<void(bool)> StatusCallback;
 
   // Persist the given refresh token on the device. Overwrites any previous
   // value. Should only be called during initial device setup. Signals
   // completion via the given callback, passing true if the operation succeeded.
   void SetAndSaveRefreshToken(const std::string& refresh_token,
                               const StatusCallback& callback);
 
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
-  // Implementation of OAuth2TokenService.
-  bool RefreshTokenIsAvailable(const std::string& account_id) const override;
-
   // Pull the robot account ID from device policy.
   virtual std::string GetRobotAccountId() const;
 
   // gaia::GaiaOAuthClient::Delegate implementation.
   void OnRefreshTokenResponse(const std::string& access_token,
                               int expires_in_seconds) override;
   void OnGetTokenInfoResponse(
       scoped_ptr<base::DictionaryValue> token_info) override;
   void OnOAuthError() override;
   void OnNetworkError(int response_code) override;
 
  protected:
-  // Implementation of OAuth2TokenService.
-  net::URLRequestContextGetter* GetRequestContext() override;
   void FetchOAuth2Token(RequestImpl* request,
                         const std::string& account_id,
                         net::URLRequestContextGetter* getter,
                         const std::string& client_id,
                         const std::string& client_secret,
                         const ScopeSet& scopes) override;
-  OAuth2AccessTokenFetcher* CreateAccessTokenFetcher(
-      const std::string& account_id,
-      net::URLRequestContextGetter* getter,
-      OAuth2AccessTokenConsumer* consumer) override;
 
  private:
   struct PendingRequest;
   friend class DeviceOAuth2TokenServiceFactory;
   friend class DeviceOAuth2TokenServiceTest;
 
   // Describes the operational state of this object.
   enum State {
     // Pending system salt / refresh token load.
     STATE_LOADING,
     // No token available.
     STATE_NO_TOKEN,
     // System salt loaded, validation not started yet.
     STATE_VALIDATION_PENDING,
     // Refresh token validation underway.
     STATE_VALIDATION_STARTED,
     // Token validation failed.
     STATE_TOKEN_INVALID,
     // Refresh token is valid.
     STATE_TOKEN_VALID,
   };
 
+  // Concrete Implementation of GetRequestContext for
+  // DeviceOAuth2TokenServiceDelegate.
+  net::URLRequestContextGetter* GetRequestContextImpl();
+
+  // Concrete Implementation of RefreshTokenIsAvailableImpl for
+  // DeviceOAuth2TokenServiceDelegate.
+  bool RefreshTokenIsAvailableImpl(const std::string& account_id) const;
+
+  // Concrete Implementation of CreateAccessTokenFetcher for
+  // DeviceOAuth2TokenServiceDelegate.
+  OAuth2AccessTokenFetcher* CreateAccessTokenFetcherImpl(
+      const std::string& account_id,
+      net::URLRequestContextGetter* getter,
+      OAuth2AccessTokenConsumer* consumer);
+
   // Invoked by CrosSettings when the robot account ID becomes available.
   void OnServiceAccountIdentityChanged();
 
   // Use DeviceOAuth2TokenServiceFactory to get an instance of this class.
   // Ownership of |token_encryptor| will be taken.
   explicit DeviceOAuth2TokenService(net::URLRequestContextGetter* getter,
                                     PrefService* local_state);
   ~DeviceOAuth2TokenService() override;
 
   // Returns the refresh token for account_id.
@@ skipping 20 matching lines @@
   // Flushes |token_save_callbacks_|, indicating the specified result.
   void FlushTokenSaveCallbacks(bool result);
 
   // Signals failure on the specified request, passing |error| as the reason.
   void FailRequest(RequestImpl* request, GoogleServiceAuthError::State error);
 
   // Dependencies.
   scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;
   PrefService* local_state_;
 
+  DeviceOAuth2TokenServiceDelegate* device_oauth2_token_service_delegate_;
+
   // Current operational state.
   State state_;
 
   // Token save callbacks waiting to be completed.
   std::vector<StatusCallback> token_save_callbacks_;
 
   // Currently open requests that are waiting while loading the system salt or
   // validating the token.
   std::vector<PendingRequest*> pending_requests_;
 
@@ skipping 11 matching lines @@
       service_account_identity_subscription_;
 
   base::WeakPtrFactory<DeviceOAuth2TokenService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceOAuth2TokenService);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_SETTINGS_DEVICE_OAUTH2_TOKEN_SERVICE_H_