
Two changes to SplitPane:
* make isVertical_ public.
* add HANDLE_DRAG_END event which is emited after handle drag end.

R=bobbrose,arv
DELTA=29  (14 added, 2 deleted, 13 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=789


git-svn-id: 35241bd708fe29f1f6c7a4322d322e99ff93b95e@753 0b95b8e8-c90f-11de-9d4f-f947ee5921c8

mdavid/closure-library,mdavid/closure-library,mdavid/closure-library