Don't create a GXPFactory when blend is SrcOver

gm/texturedomaineffect.cpp

 
 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 // This test only works with the GPU backend.
 
@@ skipping 99 matching lines @@
         SkRect renderRect = SkRect::Make(fBmp.bounds());
         renderRect.outset(kDrawPad, kDrawPad);
 
         SkScalar y = kDrawPad + kTestPad;
         for (int tm = 0; tm < textureMatrices.count(); ++tm) {
             for (size_t d = 0; d < SK_ARRAY_COUNT(texelDomains); ++d) {
                 SkScalar x = kDrawPad + kTestPad;
                 for (int m = 0; m < GrTextureDomain::kModeCount; ++m) {
                     GrTextureDomain::Mode mode = (GrTextureDomain::Mode) m;
                     GrPipelineBuilder pipelineBuilder;
+                    pipelineBuilder.setXPFactory(
+                        GrPorterDuffXPFactory::Create(SkXfermode::kSrc_Mode))->unref();
                     SkAutoTUnref<const GrFragmentProcessor> fp(
                         GrTextureDomainEffect::Create(texture, textureMatrices[tm],
                                                 GrTextureDomain::MakeTexelDomain(texture,
                                                                                 texelDomains[d]),
                                                 mode, GrTextureParams::kNone_FilterMode));
 
                     if (!fp) {
                         continue;
                     }
                     const SkMatrix viewMatrix = SkMatrix::MakeTrans(x, y);
@@ skipping 22 matching lines @@
 };
 
 // Windows builds did not like SkScalar initialization in class :(
 const SkScalar TextureDomainEffect::kDrawPad = 10.f;
 const SkScalar TextureDomainEffect::kTestPad = 10.f;
 
 DEF_GM(return new TextureDomainEffect;)
 }
 
 #endif