[Sync] Make BackendMigrator not wait for full sync cycles

chrome/browser/sync/glue/sync_backend_host.h

Index: chrome/browser/sync/glue/sync_backend_host.h
diff --git a/chrome/browser/sync/glue/sync_backend_host.h b/chrome/browser/sync/glue/sync_backend_host.h
index 5a0b0f638af4abbf0f5a731cc6ee76937ec75084..e206916c78404d0a7273dde3b5f4f62b5e55befa 100644
--- a/chrome/browser/sync/glue/sync_backend_host.h
+++ b/chrome/browser/sync/glue/sync_backend_host.h
@@ -166,9 +166,10 @@ class SyncBackendHost {
       base::Callback<void(bool)> ready_task,
       bool enable_nigori);
 
-  // Makes an asynchronous call to syncer to switch to config mode. When done
-  // syncer will call us back on FinishConfigureDataTypes.
-  virtual void StartConfiguration(Callback0::Type* callback);
+  // Tells the syncer to switch to config mode. Calls back on
+  // FinishConfigureDataTypesOnFrontendLoop when done.  Overrideable
+  // for testing.
+  virtual void StartConfiguration(bool cleanup_disabled_types);
 
   // Encrypts the specified datatypes and marks them as needing encryption on
   // other machines. This affects all machines synced to this account and all
@@ -179,6 +180,10 @@ class SyncBackendHost {
 
   syncable::ModelTypeSet GetEncryptedDataTypes() const;
 
+  // Returns the set of types for which there is no sync data.
+  // Overrideable for testing.
+  virtual syncable::ModelTypeSet GetPurgedDataTypes() const;
+
   // Activates change processing for the given data type.  This must
   // be called synchronously with the data type's model association so
   // no changes are dropped between model association and change
@@ -328,7 +333,7 @@ class SyncBackendHost {
 
     // Called on the SyncBackendHost sync_thread_ to cleanup disabled
     // types.
-    void DoRequestCleanupDisabledTypes();
+    void DoRequestCleanupDisabledTypes(const base::Closure& callback);
 
     // Called on our SyncBackendHost's |sync_thread_| to set the passphrase
     // on behalf of SyncBackendHost::SupplyPassphrase.
@@ -357,12 +362,13 @@ class SyncBackendHost {
     void DoShutdown(bool stopping_sync);
 
     // Posts a config request on the sync thread.
-    virtual void DoRequestConfig(
+    void DoRequestConfig(
         const syncable::ModelTypeBitSet& types_to_config,
         sync_api::ConfigureReason reason);
 
-    // Start the configuration mode.
-    virtual void DoStartConfiguration(Callback0::Type* callback);
+    // Starts configuration mode, cleaning up disabled types if
+    // necessary.  Calls back on FinishConfigureDataTypes when done.
+    void DoStartConfiguration(bool cleanup_disabled_types);
 
     // Set the base request context to use when making HTTP calls.
     // This method will add a reference to the context to persist it
@@ -523,7 +529,10 @@ class SyncBackendHost {
   // to safely talk back to the SyncFrontend.
   MessageLoop* const frontend_loop_;
 
-  Profile* profile_;
+  Profile* const profile_;
+
+  // Name used for debugging (set from profile_->GetDebugName()).
+  const std::string name_;
 
   sync_notifier::SyncNotifierFactory sync_notifier_factory_;