Fix lifetime of EnhancedBookmarkModel & BookmarkImageService

components/enhanced_bookmarks/bookmark_image_service.cc

 // Copyright 2014 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 "components/enhanced_bookmarks/bookmark_image_service.h"
 
 #include "base/single_thread_task_runner.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "components/bookmarks/browser/bookmark_model.h"
 #include "components/bookmarks/browser/bookmark_model_observer.h"
@@ skipping 65 matching lines @@
       (PersistentImageStore*)::operator new(sizeof(PersistentImageStore));
   store_.reset(store);
   pool_->PostNamedSequencedWorkerTask(
       kSequenceToken,
       FROM_HERE,
       base::Bind(&ConstructPersistentImageStore, store, path));
 }
 
 BookmarkImageService::~BookmarkImageService() {
   DCHECK(CalledOnValidThread());
-  enhanced_bookmark_model_->bookmark_model()->RemoveObserver(this);
   pool_->PostNamedSequencedWorkerTask(
       kSequenceToken,
       FROM_HERE,
       base::Bind(&DeleteImageStore, store_.release()));
 }
 
+void BookmarkImageService::Shutdown() {
+  DCHECK(CalledOnValidThread());
+  enhanced_bookmark_model_->bookmark_model()->RemoveObserver(this);
+  enhanced_bookmark_model_ = NULL;
+}
+
 void BookmarkImageService::SalientImageForUrl(const GURL& page_url,
                                               Callback callback) {
   DCHECK(CalledOnValidThread());
   SalientImageForUrl(page_url, true, callback);
 }
 
 void BookmarkImageService::RetrieveImageFromStore(
     const GURL& page_url,
     BookmarkImageService::Callback callback) {
   DCHECK(CalledOnValidThread());
@@ skipping 232 matching lines @@
     const BookmarkNode* node) {
 }
 
 void BookmarkImageService::BookmarkAllUserNodesRemoved(
     BookmarkModel* model,
     const std::set<GURL>& removed_urls) {
   ClearAll();
 }
 
 }  // namespace enhanced_bookmarks