Revert "SkSL is now pickier about type conversions"

This reverts commit 91c1d08bc391c997418512b9599f3acd3b2c985d.

Reason for revert: breaking everything

Original change's description:
> SkSL is now pickier about type conversions
> 
> Bug: skia:
> Change-Id: I4e8b8f229f4e4344f160b0dbb41832764d0b75bd
> Reviewed-on: https://skia-review.googlesource.com/c/188311
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
> Reviewed-by: Brian Salomon <bsalomon@google.com>

TBR=bsalomon@google.com,csmartdalton@google.com,ethannicholas@google.com

Change-Id: I670fa9215d3ca0ce738edc24e832b6d968599cb1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/c/189642
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
diff --git a/src/gpu/effects/GrConvexPolyEffect.cpp b/src/gpu/effects/GrConvexPolyEffect.cpp
index 625427a..4751fec 100644
--- a/src/gpu/effects/GrConvexPolyEffect.cpp
+++ b/src/gpu/effects/GrConvexPolyEffect.cpp
@@ -50,9 +50,8 @@
     fragBuilder->codeAppend("\t\thalf alpha = 1.0;\n");
     fragBuilder->codeAppend("\t\thalf edge;\n");
     for (int i = 0; i < cpe.getEdgeCount(); ++i) {
-        fragBuilder->codeAppendf("\t\tedge = dot(%s[%d], half3(half(sk_FragCoord.x), "
-                                                              "half(sk_FragCoord.y), "
-                                                              "1));\n",
+        fragBuilder->codeAppendf("\t\tedge = dot(%s[%d], half3(sk_FragCoord.x, sk_FragCoord.y, "
+                                                             "1));\n",
                                  edgeArrayName, i);
         if (GrProcessorEdgeTypeIsAA(cpe.getEdgeType())) {
             fragBuilder->codeAppend("\t\tedge = saturate(edge);\n");