Don't create a GXPFactory when blend is SrcOver

src/effects/SkMorphologyImageFilter.cpp

 /*
  * Copyright 2012 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 "SkMorphologyImageFilter.h"
 #include "SkBitmap.h"
 #include "SkColorPriv.h"
@@ skipping 461 matching lines @@
                            int radius,
                            GrMorphologyEffect::MorphologyType morphType,
                            float bounds[2],
                            Gr1DKernelEffect::Direction direction) {
     GrPaint paint;
     paint.addColorFragmentProcessor(GrMorphologyEffect::Create(texture,
                                                                direction,
                                                                radius,
                                                                morphType,
                                                                bounds))->unref();
+    paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
     drawContext->fillRectToRect(clip, paint, SkMatrix::I(), SkRect::Make(dstRect),
                                      SkRect::Make(srcRect));
 }
 
 void apply_morphology_rect_no_bounds(GrDrawContext* drawContext,
                                      const GrClip& clip,
                                      GrTexture* texture,
                                      const SkIRect& srcRect,
                                      const SkIRect& dstRect,
                                      int radius,
                                      GrMorphologyEffect::MorphologyType morphType,
                                      Gr1DKernelEffect::Direction direction) {
     GrPaint paint;
     paint.addColorFragmentProcessor(GrMorphologyEffect::Create(texture,
                                                                direction,
                                                                radius,
                                                                morphType))->unref();
+    paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
     drawContext->fillRectToRect(clip, paint, SkMatrix::I(), SkRect::Make(dstRect),
                                 SkRect::Make(srcRect));
 }
 
 void apply_morphology_pass(GrDrawContext* drawContext,
                            const GrClip& clip,
                            GrTexture* texture,
                            const SkIRect& srcRect,
                            const SkIRect& dstRect,
                            int radius,
@@ skipping 162 matching lines @@
                                          SkBitmap* result, SkIPoint* offset) const {
     return this->filterImageGPUGeneric(true, proxy, src, ctx, result, offset);
 }
 
 bool SkErodeImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, const Context& ctx,
                                         SkBitmap* result, SkIPoint* offset) const {
     return this->filterImageGPUGeneric(false, proxy, src, ctx, result, offset);
 }
 
 #endif