Rename ShaderType enum to ShaderVisibility

Renames ShaderType in GrGLShaderBuilder to ShaderVisibility. It is now
used solely as a bitfield. Methods that previously accepted a single
ShaderType value are split into separate calls:

 - getShader -> vsGetShader, gsGetShader, fsGetShader
 - emiitFunction -> fsEmitFunction
 - appendTextureLookup -> fsAppendTextureLookup

No change in functionality. This is a refactoring to allow us to
separate the vertex/geometry and fragment parts of GrGLShaderBuilder.

R=bsalomon@google.com

Author: cdalton@nvidia.com

Review URL: https://chromiumcodereview.appspot.com/23826002

git-svn-id: http://skia.googlecode.com/svn/trunk@11044 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/effects/GrConvolutionEffect.cpp b/src/gpu/effects/GrConvolutionEffect.cpp
index d3d1840..dd25d40 100644
--- a/src/gpu/effects/GrConvolutionEffect.cpp
+++ b/src/gpu/effects/GrConvolutionEffect.cpp
@@ -64,13 +64,13 @@
                                      const TextureSamplerArray& samplers) {
     SkString coords;
     fEffectMatrix.emitCodeMakeFSCoords2D(builder, key, &coords);
-    fImageIncrementUni = builder->addUniform(GrGLShaderBuilder::kFragment_ShaderType,
+    fImageIncrementUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                              kVec2f_GrSLType, "ImageIncrement");
     if (this->useBounds()) {
-        fBoundsUni = builder->addUniform(GrGLShaderBuilder::kFragment_ShaderType,
+        fBoundsUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                          kVec2f_GrSLType, "Bounds");
     }
-    fKernelUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_ShaderType,
+    fKernelUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
                                           kFloat_GrSLType, "Kernel", this->width());
 
     builder->fsCodeAppendf("\t\t%s = vec4(0, 0, 0, 0);\n", outputColor);
@@ -88,7 +88,7 @@
         index.appendS32(i);
         kernel.appendArrayAccess(index.c_str(), &kernelIndex);
         builder->fsCodeAppendf("\t\t%s += ", outputColor);
-        builder->appendTextureLookup(GrGLShaderBuilder::kFragment_ShaderType, samplers[0], "coord");
+        builder->fsAppendTextureLookup(samplers[0], "coord");
         if (this->useBounds()) {
             const char* bounds = builder->getUniformCStr(fBoundsUni);
             const char* component = this->direction() == Gr1DKernelEffect::kY_Direction ? "y" : "x";