Fix lifetime of EnhancedBookmarkModel & BookmarkImageService

Unregister BookmarkImageService observer from BookmarkModel in the
Shutdown method instead of the destructor to follow the two step
shutdown of the profile.

Fix a typo in the EnhancedBookmarkModel override of KeyedService
Shutdown method (could have been caught by using the OVERRIDE keyword).

BUG=None

Review URL: https://codereview.chromium.org/588233002

Cr-Commit-Position: refs/heads/master@{#296009}

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());

components/enhanced_bookmarks/bookmark_image_service.h

@@ -38,6 +38,9 @@ class BookmarkImageService : public KeyedService,
 
   typedef base::Callback<void(const gfx::Image&, const GURL& url)> Callback;
 
+  // KeyedService:
+  virtual void Shutdown() OVERRIDE;
+
   // Returns a salient image for a URL. This may trigger a network request for
   // the image if the image was not retrieved before and if a bookmark node has
   // a URL for this salient image available.  The image (which may be empty) is

components/enhanced_bookmarks/enhanced_bookmark_model.cc

@@ -93,7 +93,7 @@ EnhancedBookmarkModel::EnhancedBookmarkModel(BookmarkModel* bookmark_model,
 EnhancedBookmarkModel::~EnhancedBookmarkModel() {
 }
 
-void EnhancedBookmarkModel::ShutDown() {
+void EnhancedBookmarkModel::Shutdown() {
   FOR_EACH_OBSERVER(EnhancedBookmarkModelObserver,
                     observers_,
                     EnhancedBookmarkModelShuttingDown());

components/enhanced_bookmarks/enhanced_bookmark_model.h

@@ -38,7 +38,7 @@ class EnhancedBookmarkModel : public KeyedService,
                         const std::string& version);
   virtual ~EnhancedBookmarkModel();
 
-  virtual void ShutDown();
+  virtual void Shutdown() OVERRIDE;
 
   void AddObserver(EnhancedBookmarkModelObserver* observer);
   void RemoveObserver(EnhancedBookmarkModelObserver* observer);

components/enhanced_bookmarks/enhanced_bookmark_model_unittest.cc

@@ -51,7 +51,7 @@ class EnhancedBookmarkModelTest
 
   virtual void TearDown() OVERRIDE {
     if (model_)
-      model_->ShutDown();
+      model_->Shutdown();
     model_.reset();
     bookmark_model_.reset();
     bookmark_client_.reset();
@@ -447,7 +447,7 @@ TEST_F(EnhancedBookmarkModelTest, TestVersionField) {
 
 // Verifies that duplicate nodes are reset when the model is created.
 TEST_F(EnhancedBookmarkModelTest, ResetDuplicateNodesOnInitialization) {
-  model_->ShutDown();
+  model_->Shutdown();
 
   const BookmarkNode* parent = bookmark_model_->other_node();
   const BookmarkNode* node1 = bookmark_model_->AddURL(
@@ -563,7 +563,7 @@ TEST_F(EnhancedBookmarkModelTest, SetMultipleMetaInfo) {
 
 TEST_F(EnhancedBookmarkModelTest, ObserverShuttingDownEvent) {
   EXPECT_EQ(0, shutting_down_calls_);
-  model_->ShutDown();
+  model_->Shutdown();
   EXPECT_EQ(1, shutting_down_calls_);
   model_.reset();
 }
@@ -645,7 +645,7 @@ TEST_F(EnhancedBookmarkModelTest, ShutDownWhileResetDuplicationScheduled) {
   const BookmarkNode* node2 = AddBookmark();
   bookmark_model_->SetNodeMetaInfo(node1, "stars.id", "c_1");
   bookmark_model_->SetNodeMetaInfo(node2, "stars.id", "c_1");
-  model_->ShutDown();
+  model_->Shutdown();
   model_.reset();
   base::RunLoop().RunUntilIdle();
 }