Perform /ListAccounts check before session merge to see if there is a need for session merge at all.

chrome/browser/chromeos/login/oauth2_login_manager.h

 // Copyright (c) 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_LOGIN_OAUTH2_LOGIN_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_OAUTH2_LOGIN_MANAGER_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 97 matching lines @@
   SessionRestoreState state() { return state_; }
 
   const base::Time& session_restore_start() { return session_restore_start_; }
 
   // Returns true if the tab loading should block until session restore
   // finishes.
   bool ShouldBlockTabLoading();
 
  private:
   friend class MergeSessionLoadPageTest;
+  friend class OAuth2Test;
 
   // Session restore outcomes (for UMA).
-  enum {
+  enum SessionRestoreOutcome {
     SESSION_RESTORE_UNDEFINED = 0,
     SESSION_RESTORE_SUCCESS = 1,
     SESSION_RESTORE_TOKEN_FETCH_FAILED = 2,
     SESSION_RESTORE_NO_REFRESH_TOKEN_FAILED = 3,
     SESSION_RESTORE_OAUTHLOGIN_FAILED = 4,
     SESSION_RESTORE_MERGE_SESSION_FAILED = 5,
-    SESSION_RESTORE_COUNT = SESSION_RESTORE_MERGE_SESSION_FAILED,
+    SESSION_RESTORE_NOT_NEEDED = 6,
+    SESSION_RESTORE_COUNT = 7,
   };
 
   // Outcomes of post-merge session verification.
   // This enum is used for an UMA histogram, and hence new items should only be
   // appended at the end.
-  enum PostMergeVerificationOutcome {
+  enum MergeVerificationOutcome {
     POST_MERGE_UNDEFINED  = 0,
     POST_MERGE_SUCCESS = 1,
     POST_MERGE_NO_ACCOUNTS = 2,
     POST_MERGE_MISSING_PRIMARY_ACCOUNT = 3,
     POST_MERGE_PRIMARY_NOT_FIRST_ACCOUNT = 4,
     POST_MERGE_VERIFICATION_FAILED = 5,
     POST_MERGE_CONNECTION_FAILED = 6,
     POST_MERGE_COUNT = 7,
   };
 
@@ skipping 37 matching lines @@
   // Get the account id corresponding to the specified refresh token.
   void GetAccountIdOfRefreshToken(const std::string& refresh_token);
 
   // Attempts to fetch OAuth2 tokens by using pre-authenticated cookie jar from
   // provided |auth_profile|.
   void FetchOAuth2Tokens();
 
   // Reports when all tokens are loaded.
   void ReportOAuth2TokensLoaded();
 
+  // Checks if primary account sessions cookies are stale and restores them
+  // if needed.
+  void VerifySessionCookies();
+
   // Issue GAIA cookie recovery (MergeSession) from |refresh_token_|.
   void RestoreSessionCookies();
 
   // Checks GAIA error and figures out whether the request should be
   // re-attempted.
   bool RetryOnError(const GoogleServiceAuthError& error);
 
   // Changes |state_|, if needed fires observers (OnSessionRestoreStateChanged).
   void SetSessionRestoreState(SessionRestoreState state);
 
   // Testing helper.
   void SetSessionRestoreStartForTesting(const base::Time& time);
 
-  // Records |outcome| of post merge verification check.
-  static void RecordPostMergeOutcome(PostMergeVerificationOutcome outcome);
+  // Records |outcome| of merge verification check. |is_pre_merge| specifies
+  // if this is pre or post merge session verification.
+  static void RecordCookiesCheckOutcome(
+      bool is_pre_merge,
+      MergeVerificationOutcome outcome);
+
+  // Records successful |outcome| of merge session process.
+  void RecordSessionRestoreOutcome(SessionRestoreOutcome outcome);
 
   // Keeps the track if we have already reported OAuth2 token being loaded
   // by OAuth2TokenService.
   Profile* user_profile_;
   scoped_refptr<net::URLRequestContextGetter> auth_request_context_;
   SessionRestoreStrategy restore_strategy_;
   SessionRestoreState state_;
 
   scoped_ptr<OAuth2TokenFetcher> oauth2_token_fetcher_;
   scoped_ptr<OAuth2LoginVerifier> login_verifier_;
@@ skipping 16 matching lines @@
   // TODO(zelidrag|gspencer): Figure out how to get rid of ProfileHelper so we
   // can change the line below to ObserverList<Observer, true>.
   ObserverList<Observer, false> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(OAuth2LoginManager);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_OAUTH2_LOGIN_MANAGER_H_