Add Texture2D and Sampler GrSLTypes

src/gpu/gl/GrGLTexture.cpp

Index: src/gpu/gl/GrGLTexture.cpp
diff --git a/src/gpu/gl/GrGLTexture.cpp b/src/gpu/gl/GrGLTexture.cpp
index 6c8f901e3f1ebccc71f10dc79845303f6037ab71..9fd9ad87831ec2ff4e2fde869deae67372131145 100644
--- a/src/gpu/gl/GrGLTexture.cpp
+++ b/src/gpu/gl/GrGLTexture.cpp
@@ -15,13 +15,13 @@
 inline static GrSLType sampler_type(const GrGLTexture::IDDesc& idDesc, const GrGLGpu* gpu) {
     if (idDesc.fInfo.fTarget == GR_GL_TEXTURE_EXTERNAL) {
         SkASSERT(gpu->glCaps().glslCaps()->externalTextureSupport());
-        return kSamplerExternal_GrSLType;
+        return kTextureExternalSampler_GrSLType;
     } else if (idDesc.fInfo.fTarget == GR_GL_TEXTURE_RECTANGLE) {
         SkASSERT(gpu->glCaps().rectangleTextureSupport());
-        return kSampler2DRect_GrSLType;
+        return kTexture2DRectSampler_GrSLType;
     } else {
         SkASSERT(idDesc.fInfo.fTarget == GR_GL_TEXTURE_2D);
-        return kSampler2D_GrSLType;
+        return kTexture2DSampler_GrSLType;
     }
 }