Bug 1575305 Part 1 - Remove an unneeded condition used for ::-moz-column-content. r=dbaron

Before bug 1411422, a ::-moz-column-content has height:100%, so it could
go into this path if ColumnSet's available block-size is unconstrained.

However, after bug 1411422, height:100% was removed for
::-moz-column-content. That is, its computed block-size is
unconstrained, so it can't go into this path. This applies regardless of
whether column-span is enabled or not.

Differential Revision: https://phabricator.services.mozilla.com/D42708

--HG--
extra : moz-landing-system : lando

layout/generic/nsBlockFrame.cpp

@@ -1772,10 +1772,7 @@ void nsBlockFrame::ComputeFinalSize(const ReflowInput& aReflowInput,
     blockEndEdgeOfChildren = std::max(blockEndEdgeOfChildren, floatHeight);
   }
 
-  if (NS_UNCONSTRAINEDSIZE != aReflowInput.ComputedBSize() &&
-      (!GetParent()->IsColumnSetFrame() ||
-       aReflowInput.mParentReflowInput->AvailableBSize() ==
-           NS_UNCONSTRAINEDSIZE)) {
+  if (NS_UNCONSTRAINEDSIZE != aReflowInput.ComputedBSize()) {
     finalSize.BSize(wm) =
         ComputeFinalBSize(aReflowInput, aState.mReflowStatus,
                           aState.mBCoord + nonCarriedOutBDirMargin,