Some GrGLShaderBuilder cleanup

Review URL: https://codereview.appspot.com/6500043/



git-svn-id: http://skia.googlecode.com/svn/trunk@5322 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkSweepGradient.cpp b/src/effects/gradients/SkSweepGradient.cpp
index 5b3e4b4..15547de 100644
--- a/src/effects/gradients/SkSweepGradient.cpp
+++ b/src/effects/gradients/SkSweepGradient.cpp
@@ -458,7 +458,7 @@
                               const char* samplerName) {
     SkString t;
     t.printf("atan(- %s.y, - %s.x) * 0.1591549430918 + 0.5",
-        builder->fSampleCoords.c_str(), builder->fSampleCoords.c_str());
+        builder->defaultTexCoordsName(), builder->defaultTexCoordsName());
     this->emitColorLookup(builder, t.c_str(), outputColor, samplerName);
 }