[Sync] Support open tabs experiment enabling before sync setup completion.

chrome/browser/sync/glue/sync_backend_host.cc

 // Copyright (c) 2011 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.
 
 #include "build/build_config.h"
 
 #include "chrome/browser/sync/glue/sync_backend_host.h"
 
 #include <algorithm>
 #include <map>
@@ skipping 801 matching lines @@
 
   SVLOG(1) << "Got snapshot " << snapshot->ToString();
 
   const syncable::ModelTypeSet& to_migrate =
       snapshot->syncer_status.types_needing_local_migration;
   if (!to_migrate.empty())
     host_->frontend_->OnMigrationNeededForTypes(to_migrate);
 
   // Process any changes to the datatypes we're syncing.
   // TODO(sync): add support for removing types.
-  syncable::ModelTypeSet to_add;
-  if (host_->initialized() &&
-      sync_manager()->ReceivedExperimentalTypes(&to_add)) {
-    host_->frontend_->OnDataTypesChanged(to_add);
-  }
+  if (host_->initialized())
+    host_->AddExperimentalTypes();
 
   // If we are waiting for a configuration change, check here to see
   // if this sync cycle has initialized all of the types we've been
   // waiting for.
   if (host_->pending_download_state_.get()) {
     scoped_ptr<PendingConfigureDataTypesState> state(
         host_->pending_download_state_.release());
     DCHECK(
         std::includes(state->types_to_add.begin(), state->types_to_add.end(),
                       state->added_types.begin(), state->added_types.end()));
@@ skipping 30 matching lines @@
 void SyncBackendHost::Core::HandleClearServerDataFailedOnFrontendLoop() {
   if (!host_ || !host_->frontend_)
     return;
   host_->frontend_->OnClearServerDataFailed();
 }
 
 void SyncBackendHost::Core::FinishConfigureDataTypesOnFrontendLoop() {
   host_->FinishConfigureDataTypesOnFrontendLoop();
 }
 
+void SyncBackendHost::AddExperimentalTypes() {
+  CHECK(initialized());
+  syncable::ModelTypeSet to_add;
+  if (core_->sync_manager()->ReceivedExperimentalTypes(&to_add))
+    frontend_->OnDataTypesChanged(to_add);
+}
+
 void SyncBackendHost::HandleInitializationCompletedOnFrontendLoop(
     const WeakHandle<JsBackend>& js_backend, bool success) {
   DCHECK_NE(NOT_ATTEMPTED, initialization_state_);
   if (!frontend_)
     return;
 
   // We've at least created the sync manager at this point, but if that is all
   // we've done we're just beginning the initialization process.
   if (initialization_state_ == CREATING_SYNC_MANAGER)
     initialization_state_ = NOT_INITIALIZED;
@@ skipping 30 matching lines @@
     case DOWNLOADING_NIGORI:
       initialization_state_ = REFRESHING_ENCRYPTION;
       RefreshEncryption(
           base::Bind(
               &SyncBackendHost::Core::
                   HandleInitializationCompletedOnFrontendLoop,
               core_.get(), js_backend, true));
       break;
     case REFRESHING_ENCRYPTION:
       initialization_state_ = INITIALIZED;
+      // Now that we've downloaded the nigori node, we can see if there are any
+      // experimental types to enable. This should be done before we inform
+      // the frontend to ensure they're visible in the customize screen.
+      AddExperimentalTypes();
       frontend_->OnBackendInitialized(js_backend, true);
       // Now that we're fully initialized, kick off a server
       // reachability check.
       sync_thread_.message_loop()->PostTask(
           FROM_HERE,
           NewRunnableMethod(
               core_.get(),
               &SyncBackendHost::Core::DoCheckServerReachable));
       break;
     default:
@@ skipping 99 matching lines @@
       FROM_HERE,
       base::Bind(&SyncBackendHost::Core::DoRefreshEncryption,
                  core_.get(), sync_thread_done_callback));
 }
 
 #undef SVLOG
 
 #undef SLOG
 
 }  // namespace browser_sync