Make GPU coord transforms automatic

src/effects/gradients/SkRadialGradient.cpp

Index: src/effects/gradients/SkRadialGradient.cpp
diff --git a/src/effects/gradients/SkRadialGradient.cpp b/src/effects/gradients/SkRadialGradient.cpp
index 923d31fe777573ff1ff63e5ee2f50577c9e87f85..8bac12a6021e3eb6418f02d88bb139fe578c7ef8 100644
--- a/src/effects/gradients/SkRadialGradient.cpp
+++ b/src/effects/gradients/SkRadialGradient.cpp
@@ -481,6 +481,7 @@ public:
                           EffectKey,
                           const char* outputColor,
                           const char* inputColor,
+                          const TransformedCoordsArray&,
                           const TextureSamplerArray&) SK_OVERRIDE;
 
     static EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
@@ -557,12 +558,11 @@ void GrGLRadialGradient::emitCode(GrGLShaderBuilder* builder,
                                   EffectKey key,
                                   const char* outputColor,
                                   const char* inputColor,
+                                  const TransformedCoordsArray& coords,
                                   const TextureSamplerArray& samplers) {
     this->emitUniforms(builder, key);
-    SkString coords;
-    this->setupMatrix(builder, key, &coords);
     SkString t("length(");
-    t.append(coords);
+    t.append(builder->ensureFSCoords2D(coords, 0));
     t.append(")");
     this->emitColor(builder, t.c_str(), key, outputColor, inputColor, samplers);
 }