[Mac] "Refactor" DraggableButton into a mixin and impl.
This is because DraggableButton inherits from NSButton when a future class will
need it to inherit from NSPopupButton. Because ObjC lacks multiple inheritance,
and we want to avoid runtime trickery, this is the result.
BUG=none
TEST=Dragging download shelf and bookmark bar items works as before. Partially covered by unit tests.
Review URL: http://codereview.chromium.org/7462018
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@96433 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 79d5a3b9..701f3ddc 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -2445,6 +2445,8 @@
'browser/ui/cocoa/download/download_util_mac.mm',
'browser/ui/cocoa/draggable_button.h',
'browser/ui/cocoa/draggable_button.mm',
+ 'browser/ui/cocoa/draggable_button_mixin.h',
+ 'browser/ui/cocoa/draggable_button_mixin.mm',
'browser/ui/cocoa/drag_util.h',
'browser/ui/cocoa/drag_util.mm',
'browser/ui/cocoa/encoding_menu_controller_delegate_mac.h',
