Sync: Improve handling of database load failures

chrome/browser/sync/profile_sync_service.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 "chrome/browser/sync/profile_sync_service.h"
 
 #include <algorithm>
 #include <cstddef>
 #include <map>
 #include <set>
@@ skipping 354 matching lines @@
   InitializeBackend(!HasSyncSetupCompleted());
 
   if (!sync_global_error_.get()) {
     sync_global_error_.reset(new SyncGlobalError(this));
     GlobalErrorServiceFactory::GetForProfile(profile_)->AddGlobalError(
         sync_global_error_.get());
     AddObserver(sync_global_error_.get());
   }
 }
 
-void ProfileSyncService::Shutdown(bool sync_disabled) {
+void ProfileSyncService::Shutdown(bool delete_stale_data) {
   // First, we spin down the backend and wait for it to stop syncing completely
   // before we Stop the data type manager.  This is to avoid a late sync cycle
   // applying changes to the sync db that wouldn't get applied via
   // ChangeProcessors, leading to back-from-the-dead bugs.
   if (backend_.get())
     backend_->StopSyncingForShutdown();
 
   // Stop all data type controllers, if needed.  Note that until Stop
   // completes, it is possible in theory to have a ChangeProcessor apply a
   // change from a native model.  In that case, it will get applied to the sync
@@ skipping 20 matching lines @@
 
   // Shutdown the migrator before the backend to ensure it doesn't pull a null
   // snapshot.
   migrator_.reset();
   sync_js_controller_.AttachJsBackend(WeakHandle<JsBackend>());
 
   // Move aside the backend so nobody else tries to use it while we are
   // shutting it down.
   scoped_ptr<SyncBackendHost> doomed_backend(backend_.release());
   if (doomed_backend.get()) {
-    doomed_backend->Shutdown(sync_disabled);
+    doomed_backend->Shutdown(delete_stale_data);
 
     doomed_backend.reset();
   }
 
   scoped_runnable_method_factory_.RevokeAll();
 
   // Clear various flags.
   expect_sync_configuration_aborted_ = false;
   is_auth_in_progress_ = false;
   backend_initialized_ = false;
@@ skipping 122 matching lines @@
 
   // Shut all data types down.
   MessageLoop::current()->PostTask(FROM_HERE,
         scoped_runnable_method_factory_.NewRunnableMethod(
         &ProfileSyncService::Shutdown, true));
 }
 
 void ProfileSyncService::OnBackendInitialized(
     const WeakHandle<JsBackend>& js_backend, bool success) {
   if (!success) {
-    // If backend initialization failed, abort.  We only want to blow away
-    // state (DBs, etc) if this was a first-time scenario that failed.
+    // We may have gotten here because the sync database is corrupt.  We
+    // force its deletion, just in case.
     wizard_.Step(SyncSetupWizard::FATAL_ERROR);
-    Shutdown(!HasSyncSetupCompleted());
+    Shutdown(true);
     return;
   }
 
   backend_initialized_ = true;
 
   sync_js_controller_.AttachJsBackend(js_backend);
 
   // The very first time the backend initializes is effectively the first time
   // we can say we successfully "synced".  last_synced_time_ will only be null
   // in this case, because the pref wasn't restored on StartUp.
@@ skipping 986 matching lines @@
             << "Unrecoverable error.";
   } else {
     VLOG(0) << "ConfigureDataTypeManager not invoked because backend is not "
             << "initialized";
   }
 }
 
 const FailedDatatypesHandler& ProfileSyncService::failed_datatypes_handler() {
   return failed_datatypes_handler_;
 }