Bug 1394249 - SetNeedToCalcHasBCBorders to true when initialize nsTab…

…leFrame. r=mats

In the printing preview, we create continuous table frame if table is too
long to containing in a page. But the default value of
NeedToCalcHasBCBorders is false which means we don't calculate
HasBCBorders for continuous table frame. Thus, the border collapse is
not shown when printing preview.

MozReview-Commit-ID: IqhLSYuWj30

layout/tables/nsTableFrame.cpp

@@ -173,6 +173,9 @@ nsTableFrame::Init(nsIContent*       aContent,
   const nsStyleTableBorder* tableStyle = StyleTableBorder();
   bool borderCollapse = (NS_STYLE_BORDER_COLLAPSE == tableStyle->mBorderCollapse);
   SetBorderCollapse(borderCollapse);
+  if (borderCollapse) {
+    SetNeedToCalcHasBCBorders(true);
+  }
 
   if (!aPrevInFlow) {
     // If we're the first-in-flow, we manage the cell map & layout strategy that