ChromeOS cryptohome should be able to use gaia id as user identifier.

chromeos/dbus/session_manager_client.h

Index: chromeos/dbus/session_manager_client.h
diff --git a/chromeos/dbus/session_manager_client.h b/chromeos/dbus/session_manager_client.h
index 4fd4c0955ea287154ff95d2e8f4a68f2b7042058..d0e3566450d3e1ec1c3ef4deb9612e178b2eea0b 100644
--- a/chromeos/dbus/session_manager_client.h
+++ b/chromeos/dbus/session_manager_client.h
@@ -16,6 +16,10 @@
 #include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
+namespace cryptohome {
+class Identification;
+}
+
 namespace chromeos {
 
 // SessionManagerClient is used to communicate with the session manager.
@@ -78,7 +82,8 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
   virtual void RestartJob(const std::vector<std::string>& argv) = 0;
 
   // Starts the session for the user.
-  virtual void StartSession(const std::string& user_email) = 0;
+  virtual void StartSession(
+      const cryptohome::Identification& cryptohome_id) = 0;
 
   // Stops the current session.
   virtual void StopSession() = 0;
@@ -102,19 +107,19 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
   virtual void NotifySupervisedUserCreationFinished() = 0;
 
   // Map that is used to describe the set of active user sessions where |key|
-  // is user_id and |value| is user_id_hash.
-  typedef std::map<std::string, std::string> ActiveSessionsMap;
+  // is cryptohome id and |value| is user_id_hash.
+  using ActiveSessionsMap = std::map<cryptohome::Identification, std::string>;
 
   // The ActiveSessionsCallback is used for the RetrieveActiveSessions()
-  // method. It receives |sessions| argument where the keys are user_ids for
-  // all users that are currently active and |success| argument which indicates
-  // whether or not the request succeded.
+  // method. It receives |sessions| argument where the keys are cryptohome_ids
+  // for all users that are currently active and |success| argument which
+  // indicates whether or not the request succeded.
   typedef base::Callback<void(const ActiveSessionsMap& sessions,
                               bool success)> ActiveSessionsCallback;
 
   // Enumerates active user sessions. Usually Chrome naturally keeps track of
   // active users when they are added into current session. When Chrome is
-  // restarted after crash by session_manager it only receives user_id and
+  // restarted after crash by session_manager it only receives cryptohome id and
   // user_id_hash for one user. This method is used to retrieve list of all
   // active users.
   virtual void RetrieveActiveSessions(
@@ -131,10 +136,10 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
   virtual void RetrieveDevicePolicy(const RetrievePolicyCallback& callback) = 0;
 
   // Fetches the user policy blob stored by the session manager for the given
-  // |username|. Upon completion of the retrieve attempt, we will call the
+  // |cryptohome_id|. Upon completion of the retrieve attempt, we will call the
   // provided callback.
   virtual void RetrievePolicyForUser(
-      const std::string& username,
+      const cryptohome::Identification& cryptohome_id,
       const RetrievePolicyCallback& callback) = 0;
 
   // Same as RetrievePolicyForUser() but blocks until a reply is received, and
@@ -144,7 +149,7 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
   // considered acceptable (e.g. restarting the browser after a crash or after
   // a flag change).
   virtual std::string BlockingRetrievePolicyForUser(
-      const std::string& username) = 0;
+      const cryptohome::Identification& cryptohome_id) = 0;
 
   // Fetches the policy blob associated with the specified device-local account
   // from session manager.  |callback| is invoked up on completion.
@@ -162,11 +167,13 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
   virtual void StoreDevicePolicy(const std::string& policy_blob,
                                  const StorePolicyCallback& callback) = 0;
 
-  // Attempts to asynchronously store |policy_blob| as user policy for the given
-  // |username|. Upon completion of the store attempt, we will call callback.
-  virtual void StorePolicyForUser(const std::string& username,
-                                  const std::string& policy_blob,
-                                  const StorePolicyCallback& callback) = 0;
+  // Attempts to asynchronously store |policy_blob| as user policy for the
+  // given |cryptohome_id|. Upon completion of the store attempt, we will call
+  // callback.
+  virtual void StorePolicyForUser(
+      const cryptohome::Identification& cryptohome_id,
+      const std::string& policy_blob,
+      const StorePolicyCallback& callback) = 0;
 
   // Sends a request to store a policy blob for the specified device-local
   // account. The result of the operation is reported through |callback|.
@@ -177,7 +184,7 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
 
   // Sets the flags to be applied next time by the session manager when Chrome
   // is restarted inside an already started session for a particular user.
-  virtual void SetFlagsForUser(const std::string& username,
+  virtual void SetFlagsForUser(const cryptohome::Identification& cryptohome_id,
                                const std::vector<std::string>& flags) = 0;
 
   typedef base::Callback<void(const std::vector<std::string>& state_keys)>