Bug 1297306 - part1:remove unused NS_STYLE_CLEAR_* condition. r=xidorn

NS_STYLE_CLEAR_NONE has been defined to 0 for like forever, so this code should
never be run. Remove it.

MozReview-Commit-ID: IQ73H6QGsPX

--HG--
extra : rebase_source : 4a32e0e7cd4325b0741f542a796fd1da4de10075

layout/generic/nsLineBox.cpp

@@ -52,9 +52,6 @@ nsLineBox::nsLineBox(nsIFrame* aFrame, int32_t aCount, bool aIsBlock)
   static_assert(NS_STYLE_CLEAR_MAX <= 15,
                 "FlagBits needs more bits to store the full range of "
                 "break type ('clear') values");
-#if NS_STYLE_CLEAR_NONE > 0
-  mFlags.mBreakType = NS_STYLE_CLEAR_NONE;
-#endif
   mChildCount = aCount;
   MarkDirty();
   mFlags.mBlock = aIsBlock;