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 537 matching lines @@
       << " -- ProfileSyncService unusable: " << message;
 
   // 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 (HasSyncSetupCompleted()) {
+    UMA_HISTOGRAM_BOOLEAN("Sync.FirstBackendInitializeSuccess", success);
+  } else {
+    UMA_HISTOGRAM_BOOLEAN("Sync.RestoreBackendInitializeSuccess", 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.
-    wizard_.Step(SyncSetupWizard::FATAL_ERROR);
-    Shutdown(!HasSyncSetupCompleted());
+    // Something went unexpectedly wrong.  Play it safe: nuke our current state
+    // and prepare ourselves to try again later.
+    DisableForUser();
     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 971 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_;
 }