Bug 455665 - nsSplitterFrameInner crashes in some special case. r+sr=bzbarsky.

layout/xul/base/src/nsSplitterFrame.cpp

@@ -526,6 +526,8 @@ nsSplitterFrameInner::MouseUp(nsPresContext* aPresContext, nsGUIEvent* aEvent)
   delete[] mChildInfosAfter;
   mChildInfosBefore = nsnull;
   mChildInfosAfter = nsnull;
+  mChildInfosBeforeCount = 0;
+  mChildInfosAfterCount = 0;
 }
 
 void