Add luminance mask transfer modes.

src/pdf/SkPDFGraphicState.cpp

Index: src/pdf/SkPDFGraphicState.cpp
diff --git a/src/pdf/SkPDFGraphicState.cpp b/src/pdf/SkPDFGraphicState.cpp
index 43d22f308eb930ecc3f04464f1743367548563d3..78c17d4517274fe004b793dcffbddcf123ae8cb2 100644
--- a/src/pdf/SkPDFGraphicState.cpp
+++ b/src/pdf/SkPDFGraphicState.cpp
@@ -48,6 +48,8 @@ static const char* blend_mode_from_xfermode(SkXfermode::Mode mode) {
         case SkXfermode::kDstATop_Mode:
         case SkXfermode::kXor_Mode:
         case SkXfermode::kPlus_Mode:
+        case SkXfermode::kSrcInLum_Mode:

[vandebo (ex-Chrome), 2013/08/20 17:24:47]

These can probably be supported in the current framework. If not, we should
seriously consider if they should be added to the public framework.

+        case SkXfermode::kDstInLum_Mode:
             return NULL;
     }
     return NULL;