Bug 1571250 - Convert flags passed to ReflowChild, FinishReflowChild, SyncFrameViewAfterReflow and from GetXULLayoutFlags / GetLayoutFlags into an enum class. r=TYLin

It seems better to convert this before adding a new flag (in bug
1547759) and risking replacing the wrong 0 with a flag.

Differential Revision: https://phabricator.services.mozilla.com/D40562

layout/mathml/nsMathMLContainerFrame.cpp

@@ -788,8 +788,8 @@ void nsMathMLContainerFrame::ReflowChild(nsIFrame* aChildFrame,
 #endif
 
   nsContainerFrame::ReflowChild(aChildFrame, aPresContext, aDesiredSize,
-                                aReflowInput, 0, 0, NS_FRAME_NO_MOVE_FRAME,
-                                aStatus);
+                                aReflowInput, 0, 0,
+                                ReflowChildFlags::NoMoveFrame, aStatus);
 
   if (aDesiredSize.BlockStartAscent() == ReflowOutput::ASK_FOR_BASELINE) {
     // This will be suitable for inline frames, which are wrapped in a block.
@@ -1246,7 +1246,7 @@ void nsMathMLContainerFrame::PositionRowChildFrames(nscoord aOffsetX,
     nscoord dx = aOffsetX + child.X();
     nscoord dy = aBaseline - child.Ascent();
     FinishReflowChild(child.Frame(), PresContext(), child.GetReflowOutput(),
-                      nullptr, dx, dy, 0);
+                      nullptr, dx, dy, ReflowChildFlags::Default);
     ++child;
   }
 }