Refactor how we store and use samplers in Ganesh

src/gpu/glsl/GrGLSLXferProcessor.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "glsl/GrGLSLXferProcessor.h"
 
 #include "GrXferProcessor.h"
@@ skipping 39 matching lines @@
 
         fragBuilder->codeAppend("// Read color from copy of the destination.\n");
         fragBuilder->codeAppendf("vec2 _dstTexCoord = (%s.xy - %s) * %s;",
                                  fragPos, dstTopLeftName, dstCoordScaleName);
 
         if (!topDown) {
             fragBuilder->codeAppend("_dstTexCoord.y = 1.0 - _dstTexCoord.y;");
         }
 
         fragBuilder->codeAppendf("vec4 %s = ", dstColor);
-        fragBuilder->appendTextureLookup(args.fTexSamplers[0], "_dstTexCoord", kVec2f_GrSLType);
+        fragBuilder->appendTextureLookup(uniformHandler->getSampler(args.fTexSamplers[0]),
+                                         "_dstTexCoord",
+                                         kVec2f_GrSLType);
         fragBuilder->codeAppend(";");
     }
 
     this->emitBlendCodeForDstRead(fragBuilder,
                                   uniformHandler,
                                   args.fInputColor,
                                   args.fInputCoverage,
                                   dstColor,
                                   args.fOutputPrimary,
                                   args.fOutputSecondary,
@@ skipping 28 matching lines @@
             fragBuilder->codeAppendf("%s *= %s;", outColor, srcCoverage);
             fragBuilder->codeAppendf("%s = %s;", outColorSecondary, srcCoverage);
         } else {
             fragBuilder->codeAppendf("%s = vec4(1.0);", outColorSecondary);
         }
     } else if (srcCoverage) {
         fragBuilder->codeAppendf("%s = %s * %s + (vec4(1.0) - %s) * %s;",
                                  outColor, srcCoverage, outColor, srcCoverage, dstColor);
     }
 }