[Sync] Make BackendMigrator not wait for full sync cycles

chrome/browser/sync/profile_sync_service_harness.h

Index: chrome/browser/sync/profile_sync_service_harness.h
diff --git a/chrome/browser/sync/profile_sync_service_harness.h b/chrome/browser/sync/profile_sync_service_harness.h
index 5ec8a444deb00c7ee0e4e9d85378ca9423dc605f..d72f8a1176568516a331c7b744db718555319a98 100644
--- a/chrome/browser/sync/profile_sync_service_harness.h
+++ b/chrome/browser/sync/profile_sync_service_harness.h
@@ -73,15 +73,6 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
   // since the previous one.  Returns true if a sync cycle has completed.
   bool AwaitSyncCycleCompletion(const std::string& reason);
 
-  // Blocks the caller until this harness has completed a single sync
-  // cycle, even if we're already synced.  Returns true if a sync
-  // cycle has completed.
-  //
-  // TODO(akalin): This is only used by some migration tests, pending
-  // the fix for http://crbug.com/92928.  Remove this once that is
-  // fixed.
-  bool AwaitNextSyncCycleCompletion(const std::string& reason);
-
   // Blocks the caller until the sync has been disabled for this client. Returns
   // true if sync is disabled.
   bool AwaitSyncDisabled(const std::string& reason);
@@ -89,6 +80,9 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
   // Blocks the caller until exponential backoff has been verified to happen.
   bool AwaitExponentialBackoffVerification();
 
+  // Blocks until the given set of data types are migrated.
+  bool AwaitMigration(const syncable::ModelTypeSet& expected_migrated_types);
+
   // Blocks the caller until this harness has observed that the sync engine
   // has downloaded all the changes seen by the |partner| harness's client.
   bool WaitUntilTimestampMatches(
@@ -213,6 +207,12 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
     // backoffs are triggered correctly.
     WAITING_FOR_EXPONENTIAL_BACKOFF_VERIFICATION,
 
+    // The sync client is waiting for migration to start.
+    WAITING_FOR_MIGRATION_TO_START,
+
+    // The sync client is waiting for migration to finish.
+    WAITING_FOR_MIGRATION_TO_FINISH,
+
     // The client verification is complete. We don't care about the state of
     // the syncer any more.
     WAITING_FOR_NOTHING,
@@ -238,6 +238,9 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
   // Indicates that the operation being waited on is complete.
   void SignalStateComplete();
 
+  // Updates the migration state we're interested in.
+  void UpdateMigrationState();
+
   // Finite state machine for controlling state.  Returns true only if a state
   // change has taken place.
   bool RunStateChangeMachine();
@@ -246,10 +249,6 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
   bool AwaitStatusChangeWithTimeout(int timeout_milliseconds,
                                     const std::string& reason);
 
-  // Used by AwaitSyncCycleCompletion() and
-  // AwaitNextSyncCycleCompletion().
-  bool AwaitSyncCycleCompletionHelper(const std::string& reason);
-
   // Returns true if the sync client has no unsynced items.
   bool IsSynced();
 
@@ -290,6 +289,14 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
   std::string username_;
   std::string password_;
 
+  // The current set of data types pending migration.  Used by
+  // AwaitMigration().
+  syncable::ModelTypeSet pending_migration_types_;
+
+  // The set of data types that have undergone migration.  Used by
+  // AwaitMigration().
+  syncable::ModelTypeSet migrated_types_;
+
   // Used for logging.
   const std::string profile_debug_name_;