[Sync] Remove CleanupDisabledTypes command and move purge logic into SyncManager.

sync/internal_api/sync_manager_impl.cc

Index: sync/internal_api/sync_manager_impl.cc
diff --git a/sync/internal_api/sync_manager_impl.cc b/sync/internal_api/sync_manager_impl.cc
index 6a164d8f0ff2aac4ff56893cfc13914c323e1737..807d3bcf8e2d7fb44e340b813aed46504660aeb4 100644
--- a/sync/internal_api/sync_manager_impl.cc
+++ b/sync/internal_api/sync_manager_impl.cc
@@ -344,6 +344,19 @@ void SyncManagerImpl::ConfigureSyncer(
   DCHECK(!ready_task.is_null());
   DCHECK(!retry_task.is_null());
 
+  // Cleanup any types that might have just been disabled.
+  ModelTypeSet previous_types = ModelTypeSet::All();
+  if (!session_context_->routing_info().empty())
+    previous_types = GetRoutingInfoTypes(session_context_->routing_info());
+  if (!PurgeDisabledTypes(previous_types,
+                          GetRoutingInfoTypes(new_routing_info))) {
+    // We failed to cleanup the types. Invoke the ready task without actually
+    // configuring any types. The caller should detect this as a configuration
+    // failure and act appropriately.
+    ready_task.Run();
+    return;
+  }
+
   // TODO(zea): set this based on whether cryptographer has keystore
   // encryption key or not (requires opening a transaction). crbug.com/129665.
   ConfigurationParams::KeystoreKeyStatus keystore_key_status =
@@ -462,7 +475,19 @@ bool SyncManagerImpl::Init(
     // trigger the migration logic before the backend is initialized, resulting
     // in crashes. We therefore detect and purge any partially synced types as
     // part of initialization.
-    if (!PurgePartiallySyncedTypes())
+    //
+    // Similarly, a type may have been disabled previously, but we didn't
+    // manage to purge. Ensure we cleanup any disabled types before starting up.
+    //
+    // Note: If either of these methods fail, we have directory corruption and
+    // cannot continue.
+    // TODO(rlarocque): remove the PurgeDisabledTypes call once we no longer
+    // initialize the session context with the enabled types (purging disabled
+    // types will be done within ConfigureSyncer).
+    if (!PurgePartiallySyncedTypes() ||
+        !PurgeDisabledTypes(
+            ModelTypeSet::All(),
+            GetRoutingInfoTypes(session_context_->routing_info())))
       success = false;
 
     // Cryptographer should only be accessed while holding a
@@ -710,6 +735,19 @@ bool SyncManagerImpl::PurgePartiallySyncedTypes() {
   return directory()->PurgeEntriesWithTypeIn(partially_synced_types);
 }
 
+bool SyncManagerImpl::PurgeDisabledTypes(
+    ModelTypeSet previously_enabled_types,
+    ModelTypeSet currently_enabled_types) {
+  ModelTypeSet disabled_types = Difference(previously_enabled_types,
+                                           currently_enabled_types);
+  if (disabled_types.Empty())
+    return true;
+
+  DVLOG(1) << "Purging disabled types "
+           << ModelTypeSetToString(disabled_types);
+  return directory()->PurgeEntriesWithTypeIn(disabled_types);
+}
+
 void SyncManagerImpl::UpdateCredentials(
     const SyncCredentials& credentials) {
   DCHECK(thread_checker_.CalledOnValidThread());