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/SkTwoPointRadialGradient.cpp b/src/effects/gradients/SkTwoPointRadialGradient.cpp
index d85be5d..ac0b0bd 100644
--- a/src/effects/gradients/SkTwoPointRadialGradient.cpp
+++ b/src/effects/gradients/SkTwoPointRadialGradient.cpp
@@ -530,7 +530,7 @@
                                                                          colors, stops, colorCount,
                                                                          tm));
     SkPaint paint;
-    return shader->asNewEffect(context, paint);
+    return shader->asNewEffect(context, paint, NULL);
 }
 
 /////////////////////////////////////////////////////////////////////
@@ -670,13 +670,21 @@
 
 /////////////////////////////////////////////////////////////////////
 
-GrEffectRef* SkTwoPointRadialGradient::asNewEffect(GrContext* context, const SkPaint&) const {
+GrEffectRef* SkTwoPointRadialGradient::asNewEffect(GrContext* context, const SkPaint&,
+                                                   const SkMatrix* localMatrix) const {
     SkASSERT(NULL != context);
     // invert the localM, translate to center1 (fPtsToUni), rotate so center2 is on x axis.
     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);
 
     SkScalar diffLen = fDiff.length();