Don't crash when we get a drag-ended after being detached

Removing view groups during a drag would cause an NPE here.  The
child views will still get the drag-ended event as expected.

Bug 8298439

Change-Id: I665ba1d139e8aaa820f5f515186bc4ce8bcdb1ea

parent a729a34a

core/java/android/view/ViewGroup.java

+4 −2

Original line number	Diff line number	Diff line
		@@ -1162,9 +1162,11 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager
		}

		mDragNotifiedChildren.clear();
		if (mCurrentDrag != null) {
		mCurrentDrag.recycle();
		mCurrentDrag = null;
		}
		}

		// We consider drag-ended to have been handled if one of our children
		// had offered to handle the drag.