Make all blending up to GrOptDrawState be handled by the xp/xp factory.

src/gpu/GrPaint.cpp

Index: src/gpu/GrPaint.cpp
diff --git a/src/gpu/GrPaint.cpp b/src/gpu/GrPaint.cpp
index 443e1c0abf71a1e81471956989b9626f3cfe2980..5ed573a88bbb0906a4dd8d4ea210368f672d6b39 100644
--- a/src/gpu/GrPaint.cpp
+++ b/src/gpu/GrPaint.cpp
@@ -8,7 +8,6 @@
 
 #include "GrPaint.h"
 
-#include "GrBlend.h"
 #include "GrProcOptInfo.h"
 #include "effects/GrPorterDuffXferProcessor.h"
 #include "effects/GrSimpleTextureEffect.h"
@@ -52,73 +51,20 @@ bool GrPaint::isOpaqueAndConstantColor(GrColor* color) const {
 void GrPaint::resetStages() {
     fColorStages.reset();
     fCoverageStages.reset();
-    fXPFactory.reset(GrPorterDuffXPFactory::Create(SkXfermode::kSrcOver_Mode));
+    fXPFactory.reset(GrPorterDuffXPFactory::Create(SkXfermode::kSrc_Mode));
 }
 
 bool GrPaint::getOpaqueAndKnownColor(GrColor* solidColor,
                                      uint32_t* solidColorKnownComponents) const {
 
-    // TODO: Share this implementation with GrDrawState
-    
     GrProcOptInfo coverageProcInfo;
     coverageProcInfo.calcWithInitialValues(fCoverageStages.begin(), this->numCoverageStages(),
                                            0xFFFFFFFF, kRGBA_GrColorComponentFlags, true);
-
-    if (!coverageProcInfo.isSolidWhite()) {
-        return false;
-    }
-
     GrProcOptInfo colorProcInfo;
     colorProcInfo.calcWithInitialValues(fColorStages.begin(), this->numColorStages(), fColor,
                                         kRGBA_GrColorComponentFlags, false);
 
-    SkASSERT((NULL == solidColor) == (NULL == solidColorKnownComponents));
-
-    GrBlendCoeff srcCoeff = fSrcBlendCoeff;
-    GrBlendCoeff dstCoeff = fDstBlendCoeff;
-    GrSimplifyBlend(&srcCoeff, &dstCoeff, colorProcInfo.color(), colorProcInfo.validFlags(),
-                    0, 0, 0);
-
-    bool opaque = kZero_GrBlendCoeff == dstCoeff && !GrBlendCoeffRefsDst(srcCoeff);
-    if (solidColor) {
-        if (opaque) {
-            switch (srcCoeff) {
-                case kZero_GrBlendCoeff:
-                    *solidColor = 0;
-                    *solidColorKnownComponents = kRGBA_GrColorComponentFlags;
-                    break;
-
-                case kOne_GrBlendCoeff:
-                    *solidColor = colorProcInfo.color();
-                    *solidColorKnownComponents = colorProcInfo.validFlags();
-                    break;
-
-                // The src coeff should never refer to the src and if it refers to dst then opaque
-                // should have been false.
-                case kSC_GrBlendCoeff:
-                case kISC_GrBlendCoeff:
-                case kDC_GrBlendCoeff:
-                case kIDC_GrBlendCoeff:
-                case kSA_GrBlendCoeff:
-                case kISA_GrBlendCoeff:
-                case kDA_GrBlendCoeff:
-                case kIDA_GrBlendCoeff:
-                default:
-                    SkFAIL("srcCoeff should not refer to src or dst.");
-                    break;
-
-                // TODO: update this once GrPaint actually has a const color.
-                case kConstC_GrBlendCoeff:
-                case kIConstC_GrBlendCoeff:
-                case kConstA_GrBlendCoeff:
-                case kIConstA_GrBlendCoeff:
-                    *solidColorKnownComponents = 0;
-                    break;
-            }
-        } else {
-            solidColorKnownComponents = 0;
-        }
-    }
-    return opaque;
+    return fXPFactory->getOpaqueAndKnownColor(colorProcInfo, coverageProcInfo, solidColor,
+                                              solidColorKnownComponents);
 }