add localmatrix parameter to shader's asNewEffect

BUG=skia:
R=bsalomon@google.com, dominikg@chromium.org

Author: reed@google.com

Review URL: https://codereview.chromium.org/278963002

git-svn-id: http://skia.googlecode.com/svn/trunk@14686 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkRadialGradient.cpp b/src/effects/gradients/SkRadialGradient.cpp
index e379f36..ce4c16a 100644
--- a/src/effects/gradients/SkRadialGradient.cpp
+++ b/src/effects/gradients/SkRadialGradient.cpp
@@ -538,7 +538,7 @@
                                                                  colors, stops, colorCount,
                                                                  tm));
     SkPaint paint;
-    return shader->asNewEffect(context, paint);
+    return shader->asNewEffect(context, paint, NULL);
 }
 
 /////////////////////////////////////////////////////////////////////
@@ -559,13 +559,21 @@
 
 /////////////////////////////////////////////////////////////////////
 
-GrEffectRef* SkRadialGradient::asNewEffect(GrContext* context, const SkPaint&) const {
+GrEffectRef* SkRadialGradient::asNewEffect(GrContext* context, const SkPaint&,
+                                           const SkMatrix* localMatrix) const {
     SkASSERT(NULL != context);
 
     SkMatrix matrix;
     if (!this->getLocalMatrix().invert(&matrix)) {
         return NULL;
     }
+    if (localMatrix) {
+        SkMatrix inv;
+        if (!localMatrix->invert(&inv)) {
+            return NULL;
+        }
+        matrix.postConcat(inv);
+    }
     matrix.postConcat(fPtsToUnit);
     return GrRadialGradient::Create(context, *this, matrix, fTileMode);
 }