switched SkSL's temporary 'highfloat' type back to 'float'

Bug: skia:
Change-Id: If0debae7318b6b5b4a7cb85d458996a09931127e
Reviewed-on: https://skia-review.googlesource.com/48760
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index 0ba6a29..97d1831 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -573,7 +573,7 @@
         "\t\t%s.rgb = (%s.a < %s) ? half3(0.0) : clamp(%s.rgb / %s.a, 0.0, 1.0);",
         dColor, dColor, nearZero, dColor, dColor);
     SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[1]);
-    fragBuilder->codeAppendf("\t\thighfloat2 %s = %s + %s*(%s.",
+    fragBuilder->codeAppendf("\t\tfloat2 %s = %s + %s*(%s.",
                              cCoords, coords2D.c_str(), scaleUni, dColor);
 
     switch (displacementMap.xChannelSelector()) {