Express (GLSL expression, possibly known value) pairs as a class

src/effects/SkArithmeticMode.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkArithmeticMode.h"
 #include "SkColorPriv.h"
 #include "SkFlattenableBuffers.h"
@@ skipping 348 matching lines @@
         dstColor = builder->dstColor();
     }
 
     SkASSERT(NULL != dstColor);
     fKUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                 kVec4f_GrSLType, "k");
     const char* kUni = builder->getUniformCStr(fKUni);
 
     // We don't try to optimize for this case at all
     if (NULL == inputColor) {
-        builder->fsCodeAppendf("\t\tconst vec4 src = %s;\n", GrGLSLOnesVecf(4));
+        builder->fsCodeAppendf("\t\tconst vec4 src = vec4(1);\n");
     } else {
         builder->fsCodeAppendf("\t\tvec4 src = %s;\n", inputColor);
         if (gUseUnpremul) {
             builder->fsCodeAppendf("\t\tsrc.rgb = clamp(src.rgb / src.a, 0.0, 1.0);\n");
         }
     }
 
     builder->fsCodeAppendf("\t\tvec4 dst = %s;\n", dstColor);
     if (gUseUnpremul) {
         builder->fsCodeAppendf("\t\tdst.rgb = clamp(dst.rgb / dst.a, 0.0, 1.0);\n");
@@ skipping 41 matching lines @@
                                              background);
     }
     return true;
 }
 
 #endif
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkArithmeticMode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkArithmeticMode_scalar)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END