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/SkSweepGradient.cpp b/src/effects/gradients/SkSweepGradient.cpp
index 81ebb34..ba43571 100644
--- a/src/effects/gradients/SkSweepGradient.cpp
+++ b/src/effects/gradients/SkSweepGradient.cpp
@@ -247,7 +247,7 @@
     SkAutoTUnref<SkShader> shader(SkGradientShader::CreateSweep(center.fX, center.fY,
                                                                 colors, stops, colorCount));
     SkPaint paint;
-    return shader->asNewEffect(context, paint);
+    return shader->asNewEffect(context, paint, NULL);
 }
 
 /////////////////////////////////////////////////////////////////////
@@ -279,11 +279,19 @@
 
 /////////////////////////////////////////////////////////////////////
 
-GrEffectRef* SkSweepGradient::asNewEffect(GrContext* context, const SkPaint&) const {
+GrEffectRef* SkSweepGradient::asNewEffect(GrContext* context, const SkPaint&,
+                                          const SkMatrix* localMatrix) const {
     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 GrSweepGradient::Create(context, *this, matrix);
 }