Don't create a GXPFactory when blend is SrcOver

src/gpu/GrPipelineBuilder.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrPipelineBuilder.h"
 
 #include "GrBlend.h"
@@ skipping 13 matching lines @@
     SkDEBUGCODE(fBlockEffectRemovalCnt = 0;)
 
     for (int i = 0; i < paint.numColorFragmentProcessors(); ++i) {
         fColorFragmentProcessors.push_back(SkRef(paint.getColorFragmentProcessor(i)));
     }
 
     for (int i = 0; i < paint.numCoverageFragmentProcessors(); ++i) {
         fCoverageFragmentProcessors.push_back(SkRef(paint.getCoverageFragmentProcessor(i)));
     }
 
-    fXPFactory.reset(SkRef(paint.getXPFactory()));
+    fXPFactory.reset(SkSafeRef(paint.getXPFactory()));
 
     this->setRenderTarget(rt);
 
     // These have no equivalent in GrPaint, set them to defaults
     fDrawFace = kBoth_DrawFace;
     fStencilSettings.setDisabled();
     fFlags = 0;
 
     fClip = clip;
 
     this->setState(GrPipelineBuilder::kHWAntialias_Flag,
                    rt->isUnifiedMultisampled() && paint.isAntiAlias());
 }
 
 //////////////////////////////////////////////////////////////////////////////s
 
 bool GrPipelineBuilder::willXPNeedDstTexture(const GrCaps& caps,
                                              const GrProcOptInfo& colorPOI,
                                              const GrProcOptInfo& coveragePOI) const {
-    return this->getXPFactory()->willNeedDstTexture(caps, colorPOI, coveragePOI,
-                                                    this->hasMixedSamples());
+    if (this->getXPFactory()) {
+        return this->getXPFactory()->willNeedDstTexture(caps, colorPOI, coveragePOI,
+                                                        this->hasMixedSamples());
+    }
+    return GrPorterDuffXPFactory::SrcOverWillNeedDstTexture(caps, colorPOI, coveragePOI,
+                                                            this->hasMixedSamples());
 }
 
 void GrPipelineBuilder::AutoRestoreFragmentProcessorState::set(
                                                          const GrPipelineBuilder* pipelineBuilder) {
     if (fPipelineBuilder) {
         int m = fPipelineBuilder->numColorFragmentProcessors() - fColorEffectCnt;
         SkASSERT(m >= 0);
         for (int i = 0; i < m; ++i) {
             fPipelineBuilder->fColorFragmentProcessors.fromBack(i)->unref();
         }
@@ skipping 32 matching lines @@
 void GrPipelineBuilder::calcColorInvariantOutput(const GrDrawBatch* batch) const {
     fColorProcInfo.calcColorWithBatch(batch, fColorFragmentProcessors.begin(),
                                       this->numColorFragmentProcessors());
 }
 
 void GrPipelineBuilder::calcCoverageInvariantOutput(const GrDrawBatch* batch) const {
     fCoverageProcInfo.calcCoverageWithBatch(batch, fCoverageFragmentProcessors.begin(),
                                             this->numCoverageFragmentProcessors());
 }