mac: Fix BookmarkBarControllerTest.TestClearOnDealloc on Yosemite.

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_controller_unittest.mm

 // Copyright (c) 2012 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.
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/string16.h"
@@ skipping 329 matching lines @@
 
 class BookmarkBarControllerTest : public BookmarkBarControllerTestBase {
  public:
   base::scoped_nsobject<BookmarkBarControllerNoOpen> bar_;
 
   virtual void SetUp() override {
     BookmarkBarControllerTestBase::SetUp();
     ASSERT_TRUE(browser());
     AddCommandLineSwitches();
 
-    bar_.reset(
-      [[BookmarkBarControllerNoOpen alloc]
+    // In OSX 10.10, the owner of a nib file is retain/autoreleased during the
+    // initialization of the nib. Wrapping the constructor in an
+    // autoreleasepool ensures that tests can control the destruction timing of
+    // |bar_|.
+    @autoreleasepool {
+      bar_.reset([[BookmarkBarControllerNoOpen alloc]
           initWithBrowser:browser()
              initialWidth:NSWidth([parent_view_ frame])
                  delegate:nil
            resizeDelegate:resizeDelegate_.get()]);
+    }
 
     InstallAndToggleBar(bar_.get());
   }
 
   virtual void AddCommandLineSwitches() {}
 
   BookmarkBarControllerNoOpen* noOpenBar() {
     return (BookmarkBarControllerNoOpen*)bar_.get();
   }
 };
@@ skipping 1763 matching lines @@
                              "2f3b ] 4b ");
   actual = test::ModelStringFromNode(root);
   EXPECT_EQ(expected, actual);
 
   // Verify that the other bookmark folder can't be deleted.
   BookmarkButton *otherButton = [bar_ otherBookmarksButton];
   EXPECT_FALSE([bar_ canDragBookmarkButtonToTrash:otherButton]);
 }
 
 }  // namespace