Add gl_SampleMask functionality to fragment builders

src/gpu/glsl/GrGLSL.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLSL.h"
 #include "GrGLSLCaps.h"
 #include "SkString.h"
 
 bool GrGLSLSupportsNamedFragmentShaderOutputs(GrGLSLGeneration gen) {
     switch (gen) {
         case k110_GrGLSLGeneration:
             return false;
         case k130_GrGLSLGeneration:
         case k140_GrGLSLGeneration:
         case k150_GrGLSLGeneration:
         case k330_GrGLSLGeneration:
+        case k400_GrGLSLGeneration:
         case k310es_GrGLSLGeneration:
+        case k320es_GrGLSLGeneration:
             return true;
     }
     return false;
 }
 
 void GrGLSLAppendDefaultFloatPrecisionDeclaration(GrSLPrecision p,
                                                   const GrGLSLCaps& glslCaps,
                                                   SkString* out) {
     if (glslCaps.usesPrecisionModifiers()) {
         switch (p) {
@@ skipping 16 matching lines @@
     if (mulFactor.isOnes()) {
         *outAppend = SkString();
     }
 
     if (mulFactor.isZeros()) {
         outAppend->appendf("%s = vec4(0);", vec4VarName);
     } else {
         outAppend->appendf("%s *= %s;", vec4VarName, mulFactor.c_str());
     }
 }