added SkSL support for mustForceNegatedAtanParamToFloat cap

src/effects/gradients/SkSweepGradient.cpp

Index: src/effects/gradients/SkSweepGradient.cpp
diff --git a/src/effects/gradients/SkSweepGradient.cpp b/src/effects/gradients/SkSweepGradient.cpp
index f4ef8ab41f56b909eb59c6b6875808a38b9faae2..d62e2e55f2bd25738385b745e47826527ba18929 100644
--- a/src/effects/gradients/SkSweepGradient.cpp
+++ b/src/effects/gradients/SkSweepGradient.cpp
@@ -210,15 +210,8 @@ void GrSweepGradient::GLSLSweepProcessor::emitCode(EmitArgs& args) {
     SkString coords2D = args.fFragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
     SkString t;
     // 0.1591549430918 is 1/(2*pi), used since atan returns values [-pi, pi]
-    // On Intel GPU there is an issue where it reads the second arguement to atan "- %s.x" as an int
-    // thus must us -1.0 * %s.x to work correctly
-    if (args.fGLSLCaps->mustForceNegatedAtanParamToFloat()){
-        t.printf("(atan(- %s.y, -1.0 * %s.x) * 0.1591549430918 + 0.5)",
-                 coords2D.c_str(), coords2D.c_str());
-    } else {
-        t.printf("(atan(- %s.y, - %s.x) * 0.1591549430918 + 0.5)",
-                 coords2D.c_str(), coords2D.c_str());
-    }
+    t.printf("(atan(- %s.y, - %s.x) * 0.1591549430918 + 0.5)",
+             coords2D.c_str(), coords2D.c_str());
     this->emitColor(args.fFragBuilder,
                     args.fUniformHandler,
                     args.fGLSLCaps,