SkShader::asNewEffect Refactoring

The new signature is:

	bool asNewEffect(GrContext* context, const SkPaint& paint, GrColor* grColor, GrEffectRef** grEffect, const SkMatrix* localMatrixOrNull) const;

It will fix the hack for skcolorshader by modifying the GrColor parameter in SkGr::SkPaint2GrPaintShader.

BUG=skia:2646
R=jvanverth@google.com, bsalomon@google.com

Author: dandov@google.com

Review URL: https://codereview.chromium.org/318923005
diff --git a/src/effects/gradients/SkRadialGradient.cpp b/src/effects/gradients/SkRadialGradient.cpp
index 3b9d175..f0cb161 100644
--- a/src/effects/gradients/SkRadialGradient.cpp
+++ b/src/effects/gradients/SkRadialGradient.cpp
@@ -458,6 +458,7 @@
 #if SK_SUPPORT_GPU
 
 #include "GrTBackendEffectFactory.h"
+#include "SkGr.h"
 
 class GrGLRadialGradient : public GrGLGradientEffect {
 public:
@@ -538,7 +539,10 @@
                                                                  colors, stops, colorCount,
                                                                  tm));
     SkPaint paint;
-    return shader->asNewEffect(context, paint, NULL);
+    GrColor grColor;
+    GrEffectRef* effect;
+    shader->asNewEffect(context, paint, NULL, &grColor, &effect);
+    return effect;
 }
 
 /////////////////////////////////////////////////////////////////////
@@ -559,30 +563,37 @@
 
 /////////////////////////////////////////////////////////////////////
 
-GrEffectRef* SkRadialGradient::asNewEffect(GrContext* context, const SkPaint&,
-                                           const SkMatrix* localMatrix) const {
+bool SkRadialGradient::asNewEffect(GrContext* context, const SkPaint& paint,
+                                   const SkMatrix* localMatrix, GrColor* grColor,
+                                   GrEffectRef** grEffect) const {
     SkASSERT(NULL != context);
-
+    
     SkMatrix matrix;
     if (!this->getLocalMatrix().invert(&matrix)) {
-        return NULL;
+        return false;
     }
     if (localMatrix) {
         SkMatrix inv;
         if (!localMatrix->invert(&inv)) {
-            return NULL;
+            return false;
         }
         matrix.postConcat(inv);
     }
     matrix.postConcat(fPtsToUnit);
-    return GrRadialGradient::Create(context, *this, matrix, fTileMode);
+    
+    *grColor = SkColor2GrColorJustAlpha(paint.getColor());
+    *grEffect = GrRadialGradient::Create(context, *this, matrix, fTileMode);
+    
+    return true;
 }
 
 #else
 
-GrEffectRef* SkRadialGradient::asNewEffect(GrContext*, const SkPaint&, const SkMatrix*) const {
+bool SkRadialGradient::asNewEffect(GrContext* context, const SkPaint& paint,
+                                   const SkMatrix* localMatrix, GrColor* grColor,
+                                   GrEffectRef** grEffect) const {
     SkDEBUGFAIL("Should not call in GPU-less build");
-    return NULL;
+    return false;
 }
 
 #endif