Fix lifetime of EnhancedBookmarkModel & BookmarkImageService

components/enhanced_bookmarks/bookmark_image_service.cc

Index: components/enhanced_bookmarks/bookmark_image_service.cc
diff --git a/components/enhanced_bookmarks/bookmark_image_service.cc b/components/enhanced_bookmarks/bookmark_image_service.cc
index e481bce8c0873c2ee4f03ec044df4ba4611bba3f..066d9f93caedfa85dca7f347577069bf1968f6d6 100644
--- a/components/enhanced_bookmarks/bookmark_image_service.cc
+++ b/components/enhanced_bookmarks/bookmark_image_service.cc
@@ -83,13 +83,18 @@ BookmarkImageService::BookmarkImageService(
 
 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());