Expand modulate, add, subtract, extract component glsl helpers.
Review URL: https://codereview.chromium.org/13895006

git-svn-id: http://skia.googlecode.com/svn/trunk@8755 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrAAConvexPathRenderer.cpp b/src/gpu/GrAAConvexPathRenderer.cpp
index d011db2..22964e5 100644
--- a/src/gpu/GrAAConvexPathRenderer.cpp
+++ b/src/gpu/GrAAConvexPathRenderer.cpp
@@ -508,7 +508,7 @@
                                    "clamp(0.5 - edgeAlpha / length(gF), 0.0, 1.0);\n\t\t}\n");
 
             SkString modulate;
-            GrGLSLModulate4f(&modulate, inputColor, "edgeAlpha");
+            GrGLSLModulatef<4>(&modulate, inputColor, "edgeAlpha");
             builder->fsCodeAppendf("\t%s = %s;\n", outputColor, modulate.c_str());
 
             builder->vsCodeAppendf("\t%s = %s;\n", vsName, attrName->c_str());