Make skpaint->grpaint flow work for composing draws

src/effects/SkColorFilters.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBlitRow.h"
 #include "SkColorFilter.h"
 #include "SkColorPriv.h"
@@ skipping 56 matching lines @@
 #include "GrBlend.h"
 #include "GrInvariantOutput.h"
 #include "effects/GrXfermodeFragmentProcessor.h"
 #include "effects/GrConstColorProcessor.h"
 #include "SkGr.h"
 
 bool SkModeColorFilter::asFragmentProcessors(GrContext*, GrProcessorDataManager*,
                                              SkTDArray<const GrFragmentProcessor*>* array) const {
     if (SkXfermode::kDst_Mode != fMode) {
         SkAutoTUnref<const GrFragmentProcessor> constFP(
-            GrConstColorProcessor::Create(SkColor2GrColor(fColor),
+            GrConstColorProcessor::Create(SkColorToPremulGrColor(fColor),
                                           GrConstColorProcessor::kIgnore_InputMode));
         const GrFragmentProcessor* fp =
             GrXfermodeFragmentProcessor::CreateFromSrcProcessor(constFP, fMode);
         if (fp) {
 #ifdef SK_DEBUG
             // With a solid color input this should always be able to compute the blended color
             // (at least for coeff modes)
             if (fMode <= SkXfermode::kLastCoeffMode) {
                 static SkRandom gRand;
                 GrInvariantOutput io(GrPremulColor(gRand.nextU()), kRGBA_GrColorComponentFlags,
@@ skipping 104 matching lines @@
                     byte_to_scale(SkColorGetG(mul)),
                     byte_to_scale(SkColorGetB(mul)),
                     1);
     matrix.postTranslate(SkIntToScalar(SkColorGetR(add)),
                          SkIntToScalar(SkColorGetG(add)),
                          SkIntToScalar(SkColorGetB(add)),
                          0);
     return SkColorMatrixFilter::Create(matrix);
 }