Revert of Revert of stop calling SkScalarDiv (patchset #1 id:1 of https://codereview.chromium.org/1138263002/)

Reason for revert:
android patched, blink has rolled

Original issue's description:
> Revert of stop calling SkScalarDiv (patchset #4 id:60001 of https://codereview.chromium.org/1135053002/)
>
> Reason for revert:
> need to wait for Blink roll (and patch android)
>
> Original issue's description:
> > stop calling SkScalarDiv
> >
> > BUG=skia:
> > TBR=
> >
> > Committed: https://skia.googlesource.com/skia/+/67d71c898249a7af3523b16c6a69895a63bfae0a
>
> TBR=
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/2629697933b5cc975e45d2a45c48f803fc6cbcec

TBR=
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1135693003
diff --git a/src/effects/gradients/SkTwoPointConicalGradient_gpu.cpp b/src/effects/gradients/SkTwoPointConicalGradient_gpu.cpp
index bc70d6b..f7b3eb8 100644
--- a/src/effects/gradients/SkTwoPointConicalGradient_gpu.cpp
+++ b/src/effects/gradients/SkTwoPointConicalGradient_gpu.cpp
@@ -357,7 +357,7 @@
 
     // Scale factor 1 / (1 - focalX * focalX)
     SkScalar oneMinusF2 = 1.f - SkScalarMul(*focalX, *focalX);
-    SkScalar s = SkScalarDiv(1.f, oneMinusF2);
+    SkScalar s = SkScalarInvert(oneMinusF2);
 
 
     if (s >= 0.f) {
@@ -1115,8 +1115,7 @@
         : INHERITED(ctx, shader, matrix, tm), fInfo(info) {
         this->initClassID<CircleOutside2PtConicalEffect>();
         if (shader.getStartRadius() != shader.getEndRadius()) {
-            fTLimit = SkScalarDiv(shader.getStartRadius(),
-                                  (shader.getStartRadius() - shader.getEndRadius()));
+            fTLimit = shader.getStartRadius() / (shader.getStartRadius() - shader.getEndRadius());
         } else {
             fTLimit = SK_ScalarMin;
         }