sync: Fix crash on backend initialize failure

chrome/browser/sync/glue/sync_backend_host_core.cc

 // Copyright 2013 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/glue/sync_backend_host_core.h"
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/metrics/histogram.h"
 #include "chrome/browser/sync/glue/device_info.h"
@@ skipping 91 matching lines @@
     const base::FilePath& sync_data_folder_path,
     bool has_sync_setup_completed,
     const base::WeakPtr<SyncBackendHostImpl>& backend)
     : name_(name),
       sync_data_folder_path_(sync_data_folder_path),
       host_(backend),
       sync_loop_(NULL),
       registrar_(NULL),
       has_sync_setup_completed_(has_sync_setup_completed),
       forward_protocol_events_(false),
+      forward_type_info_(false),
       weak_ptr_factory_(this) {
   DCHECK(backend.get());
 }
 
 SyncBackendHostCore::~SyncBackendHostCore() {
   DCHECK(!sync_manager_.get());
 }
 
 void SyncBackendHostCore::OnSyncCycleCompleted(
     const syncer::sessions::SyncSessionSnapshot& snapshot) {
@@ skipping 448 matching lines @@
   if (sync_disabled)
     DeleteSyncDataFolder();
 
   host_.Reset();
   weak_ptr_factory_.InvalidateWeakPtrs();
 }
 
 void SyncBackendHostCore::DoDestroySyncManager() {
   DCHECK_EQ(base::MessageLoop::current(), sync_loop_);
   if (sync_manager_) {
+    DisableDirectoryTypeDebugInfoForwarding();
     save_changes_timer_.reset();
-    DisableDirectoryTypeDebugInfoForwarding();
     sync_manager_->RemoveObserver(this);
     sync_manager_->ShutdownOnSyncThread();
     sync_manager_.reset();
   }
 }
 
 void SyncBackendHostCore::DoConfigureSyncer(
     syncer::ConfigureReason reason,
     const DoConfigureSyncerTypes& config_types,
     const syncer::ModelSafeRoutingInfo routing_info,
@@ skipping 70 matching lines @@
     }
   }
 }
 
 void SyncBackendHostCore::DisableProtocolEventForwarding() {
   forward_protocol_events_ = false;
 }
 
 void SyncBackendHostCore::EnableDirectoryTypeDebugInfoForwarding() {
   DCHECK(sync_manager_);
+
+  forward_type_info_ = true;
+
   if (!sync_manager_->HasDirectoryTypeDebugInfoObserver(this))
     sync_manager_->RegisterDirectoryTypeDebugInfoObserver(this);
   sync_manager_->RequestEmitDebugInfo();
 }
 
 void SyncBackendHostCore::DisableDirectoryTypeDebugInfoForwarding() {
   DCHECK(sync_manager_);
+
+  if (!forward_type_info_)
+    return;
+
+  forward_type_info_ = false;
+
   if (sync_manager_->HasDirectoryTypeDebugInfoObserver(this))
     sync_manager_->UnregisterDirectoryTypeDebugInfoObserver(this);
 }
 
 void SyncBackendHostCore::DeleteSyncDataFolder() {
   DCHECK_EQ(base::MessageLoop::current(), sync_loop_);
   if (base::DirectoryExists(sync_data_folder_path_)) {
     if (!base::DeleteFile(sync_data_folder_path_, true))
       SLOG(DFATAL) << "Could not delete the Sync Data folder.";
   }
@@ skipping 38 matching lines @@
       this, &SyncBackendHostCore::SaveChanges);
 }
 
 void SyncBackendHostCore::SaveChanges() {
   DCHECK_EQ(base::MessageLoop::current(), sync_loop_);
   sync_manager_->SaveChanges();
 }
 
 }  // namespace browser_sync