Update SkClipStack's bound computation

I believe this was originally added to make Raster & GPU rendering more similar. I think we've moved on from there.

Change-Id: Ic980f3308fbd427e5857b720488c91383a32a149
Reviewed-on: https://skia-review.googlesource.com/30761
Reviewed-by: Stan Iliev <stani@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

src/core/SkClipStack.cpp

@@ -407,7 +407,7 @@ void SkClipStack::Element::updateBoundAndGenID(const Element* prior) {
     }
 
     if (!fDoAA) {
-        fFiniteBound.set(SkScalarFloorToScalar(fFiniteBound.fLeft+0.45f),
+        fFiniteBound.set(SkScalarRoundToScalar(fFiniteBound.fLeft),
                          SkScalarRoundToScalar(fFiniteBound.fTop),
                          SkScalarRoundToScalar(fFiniteBound.fRight),
                          SkScalarRoundToScalar(fFiniteBound.fBottom));