added SkSL support for mustForceNegatedAtanParamToFloat cap

src/sksl/SkSLMain.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "stdio.h"
 #include <fstream>
 #include "SkSLCompiler.h"
 
 bool endsWith(const std::string& s, const std::string& ending) {
     if (s.length() >= ending.length()) {
         return (0 == s.compare(s.length() - ending.length(), ending.length(), ending));
     }
     return false;
 }
 
 static SkSL::GLCaps default_caps() {
     return { 
              400, 
              SkSL::GLCaps::kGL_Standard,
              false, // isCoreProfile
              false, // usesPrecisionModifiers;
              false, // mustDeclareFragmentShaderOutput
-             true   // canUseMinAndAbsTogether
+             true,  // canUseMinAndAbsTogether
+             false  // mustForceNegatedAtanParamToFloat
            };
 }
 
 /**
  * Very simple standalone executable to facilitate testing.
  */
 int main(int argc, const char** argv) {
     if (argc != 3) {
         printf("usage: skslc <input> <output>\n");
         exit(1);
@@ skipping 36 matching lines @@
             exit(3);
         }
         if (out.rdstate()) {
             printf("error writing '%s'\n", argv[2]);
             exit(4);
         }
     } else {
         printf("expected output filename to end with '.spirv' or '.glsl'");
     }
 }