Broken drag targets include: tab strip, omnibox, find bar, bookmarks bar, content area.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f7c5cdae6cfe18aebf5d0fe8d528f64910443368

commit f7c5cdae6cfe18aebf5d0fe8d528f64910443368
Author: erikchen <erikchen@chromium.org>
Date: Sun Apr 03 03:20:53 2016

Refactor more clipboard/bookmark logic.

Move logic from bookmark_pasteboard_helper_mac.mm into clipboard_util_mac.mm.
This fixes drag and drop into the tab strip, find bar, and omnibox.

BUG= 600018 

Review URL: https://codereview.chromium.org/1855583002

Cr-Commit-Position: refs/heads/master@{#384823}

[modify] https://crrev.com/f7c5cdae6cfe18aebf5d0fe8d528f64910443368/chrome/browser/ui/cocoa/url_drop_target.mm
[modify] https://crrev.com/f7c5cdae6cfe18aebf5d0fe8d528f64910443368/components/bookmarks/browser/bookmark_pasteboard_helper_mac.mm
[modify] https://crrev.com/f7c5cdae6cfe18aebf5d0fe8d528f64910443368/ui/base/clipboard/clipboard_mac.mm
[modify] https://crrev.com/f7c5cdae6cfe18aebf5d0fe8d528f64910443368/ui/base/clipboard/clipboard_util_mac.h
[modify] https://crrev.com/f7c5cdae6cfe18aebf5d0fe8d528f64910443368/ui/base/clipboard/clipboard_util_mac.mm

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1b238394bd8e9cd37faa7957d274706344165b2d

commit 1b238394bd8e9cd37faa7957d274706344165b2d
Author: erikchen <erikchen@chromium.org>
Date: Mon Apr 04 16:51:55 2016

mac: More bookmark pasteboard fixes.

Wrap all references to kBookmarkButtonDragType and
kBookmarkDictionaryListPboardType in ui::ClipboardUtil::UTIForPasteboardType().

BUG= 600018 

Review URL: https://codereview.chromium.org/1855783002

Cr-Commit-Position: refs/heads/master@{#384930}

[modify] https://crrev.com/1b238394bd8e9cd37faa7957d274706344165b2d/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_controller.mm
[modify] https://crrev.com/1b238394bd8e9cd37faa7957d274706344165b2d/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller.mm
[modify] https://crrev.com/1b238394bd8e9cd37faa7957d274706344165b2d/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_view.mm
[modify] https://crrev.com/1b238394bd8e9cd37faa7957d274706344165b2d/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_view_unittest.mm
[modify] https://crrev.com/1b238394bd8e9cd37faa7957d274706344165b2d/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_view_cocoa.mm
[modify] https://crrev.com/1b238394bd8e9cd37faa7957d274706344165b2d/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_view_cocoa_unittest.mm
[modify] https://crrev.com/1b238394bd8e9cd37faa7957d274706344165b2d/chrome/browser/ui/cocoa/bookmarks/bookmark_button.mm
[modify] https://crrev.com/1b238394bd8e9cd37faa7957d274706344165b2d/chrome/browser/ui/cocoa/bookmarks/bookmark_folder_target.mm

I tried this on two other machines, and drag and drop seemed to work fine on Chrome stable. Bah my machine must have been borked.