Refactor AO2TS to make it easier to componentize.

google_apis/gaia/oauth2_token_service_delegate.h

Index: google_apis/gaia/oauth2_token_service_delegate.h
diff --git a/google_apis/gaia/oauth2_token_service_delegate.h b/google_apis/gaia/oauth2_token_service_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..cb38c2eb0e5a3a60a16db7dfbf16129ee71a3da8
--- /dev/null
+++ b/google_apis/gaia/oauth2_token_service_delegate.h
@@ -0,0 +1,87 @@
+// Copyright 2015 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 GOOGLE_APIS_GAIA_OAUTH2_TOKEN_SERVICE_DELEGATE_H_
+#define GOOGLE_APIS_GAIA_OAUTH2_TOKEN_SERVICE_DELEGATE_H_
+
+#include "base/observer_list.h"
+#include "google_apis/gaia/gaia_auth_util.h"
+#include "google_apis/gaia/oauth2_token_service.h"
+
+namespace net {
+class URLRequestContextGetter;
+}
+
+class SigninClient;
+
+// Abstract base class to fetch and maintain refresh tokens from various
+// entities. Concrete subclasses should implement RefreshTokenIsAvailable and
+// CreateAccessTokenFetcher properly.
+class OAuth2TokenServiceDelegate {
+ public:
+  OAuth2TokenServiceDelegate();
+  virtual ~OAuth2TokenServiceDelegate();
+
+  virtual OAuth2AccessTokenFetcher* CreateAccessTokenFetcher(
+      const std::string& account_id,
+      net::URLRequestContextGetter* getter,
+      OAuth2AccessTokenConsumer* consumer) = 0;
+
+  virtual bool RefreshTokenIsAvailable(const std::string& account_id) const = 0;
+  virtual void UpdateAuthError(const std::string& account_id,
+                               const GoogleServiceAuthError& error){};
+
+  virtual std::vector<std::string> GetAccounts();
+  virtual void RevokeAllCredentials(){};
+
+  virtual void InvalidateAccessToken(const std::string& account_id,
+                                     const std::string& client_id,
+                                     const std::set<std::string>& scopes,
+                                     const std::string& access_token) {}
+
+  virtual void Shutdown() {}
+  virtual void LoadCredentials(const std::string& primary_account_id) {}
+  virtual void UpdateCredentials(const std::string& account_id,
+                                 const std::string& refresh_token) {}
+  virtual void RevokeCredentials(const std::string& account_id) {}
+  virtual net::URLRequestContextGetter* GetRequestContext() const;
+
+  void ValidateAccountId(const std::string& account_id) const;
+
+  // Add or remove observers of this token service.
+  void AddObserver(OAuth2TokenService::Observer* observer);
+  void RemoveObserver(OAuth2TokenService::Observer* observer);
+
+ protected:
+  // Called by subclasses to notify observers.
+  virtual void FireRefreshTokenAvailable(const std::string& account_id);
+  virtual void FireRefreshTokenRevoked(const std::string& account_id);
+  virtual void FireRefreshTokensLoaded();
+
+  // Helper class to scope batch changes.
+  class ScopedBatchChange {
+   public:
+    explicit ScopedBatchChange(OAuth2TokenServiceDelegate* delegate);
+    ~ScopedBatchChange();
+
+   private:
+    OAuth2TokenServiceDelegate* delegate_;  // Weak.
+    DISALLOW_COPY_AND_ASSIGN(ScopedBatchChange);
+  };
+
+ private:
+  // List of observers to notify when refresh token availability changes.
+  // Makes sure list is empty on destruction.
+  base::ObserverList<OAuth2TokenService::Observer, true> observer_list_;
+
+  void StartBatchChanges();
+  void EndBatchChanges();
+
+  // The depth of batch changes.
+  int batch_change_depth_;
+
+  DISALLOW_COPY_AND_ASSIGN(OAuth2TokenServiceDelegate);
+};
+
+#endif  // GOOGLE_APIS_GAIA_OAUTH2_TOKEN_SERVICE_DELEGATE_H_