Implement support for KHR_blend_equation_advanced

src/core/SkXfermode.cpp

Index: src/core/SkXfermode.cpp
diff --git a/src/core/SkXfermode.cpp b/src/core/SkXfermode.cpp
index ba9670a9dbc1aa9222912ea672c0b8567ce65341..5b5c6a17a5a5e5ee8a69f19835fd1fd1146fd2c4 100644
--- a/src/core/SkXfermode.cpp
+++ b/src/core/SkXfermode.cpp
@@ -672,7 +672,7 @@ bool SkXfermode::asFragmentProcessor(GrFragmentProcessor**, GrTexture*) const {
     return false;
 }
 
-bool SkXfermode::asXPFactory(GrXPFactory**) const {
+bool SkXfermode::asXPFactory(const GrContext*, GrXPFactory**) const {
     return false;
 }
 
@@ -680,18 +680,18 @@ bool SkXfermode::asXPFactory(GrXPFactory**) const {
 #if SK_SUPPORT_GPU
 #include "effects/GrPorterDuffXferProcessor.h"
 
-bool SkXfermode::AsXPFactory(SkXfermode* xfermode, GrXPFactory** xpf) {
+bool SkXfermode::AsXPFactory(SkXfermode* xfermode, const GrContext* context, GrXPFactory** xpf) {
     if (NULL == xfermode) {
         if (xpf) {
             *xpf = GrPorterDuffXPFactory::Create(kSrcOver_Mode);
         }
         return true;
     } else {
-        return xfermode->asXPFactory(xpf);
+        return xfermode->asXPFactory(context, xpf);
     }
 }
 #else
-bool SkXfermode::AsXPFactory(SkXfermode* xfermode, GrXPFactory** xpf) {
+bool SkXfermode::AsXPFactory(SkXfermode*, const GrContext*, GrXPFactory**) {
     return false;
 }
 #endif
@@ -935,6 +935,7 @@ void SkProcCoeffXfermode::xferA8(SkAlpha* SK_RESTRICT dst,
 }
 
 #if SK_SUPPORT_GPU
+#include "effects/GrAdvancedEquationXferProcessor.h"
 #include "effects/GrCustomXfermode.h"
 
 bool SkProcCoeffXfermode::asFragmentProcessor(GrFragmentProcessor** fp,
@@ -949,7 +950,7 @@ bool SkProcCoeffXfermode::asFragmentProcessor(GrFragmentProcessor** fp,
     return false;
 }
 
-bool SkProcCoeffXfermode::asXPFactory(GrXPFactory** xp) const {
+bool SkProcCoeffXfermode::asXPFactory(const GrContext* context, GrXPFactory** xp) const {
     if (CANNOT_USE_COEFF != fSrcCoeff) {
         if (xp) {
             *xp = GrPorterDuffXPFactory::Create(fMode);
@@ -958,6 +959,14 @@ bool SkProcCoeffXfermode::asXPFactory(GrXPFactory** xp) const {
         return true;
     }
 
+    if (GrAdvancedEquationXPFactory::IsSupported(context, fMode)) {
+        if (xp) {
+            *xp = GrAdvancedEquationXPFactory::Create(context, fMode);
+            SkASSERT(*xp);
+        }
+        return true;
+    }
+
     if (GrCustomXfermode::IsSupportedMode(fMode)) {
         if (xp) {
             *xp = GrCustomXfermode::CreateXPFactory(fMode);