DM: PDFSink sets rasterizer keyword

dm/DMSrcSink.cpp

Index: dm/DMSrcSink.cpp
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index 25b5f7b4609c615ee4973c5da44eaa6e83a49fd9..96a0ab1a3ef08c04b9067ca2092e7defe77ea2ff 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -924,7 +924,7 @@ static Error draw_skdocument(const Src& src, SkDocument* doc, SkWStream* dst) {
     return "";
 }
 
-PDFSink::PDFSink() {}
+PDFSink::PDFSink(const char* rasterizer) : fRasterizer(rasterizer) {}
 
 Error PDFSink::draw(const Src& src, SkBitmap*, SkWStream* dst, SkString*) const {
     SkAutoTUnref<SkDocument> doc(SkDocument::CreatePDF(dst));
@@ -936,6 +936,9 @@ Error PDFSink::draw(const Src& src, SkBitmap*, SkWStream* dst, SkString*) const
     info.emplace_back(SkString("Subject"),
                       SkString("rendering correctness test"));
     info.emplace_back(SkString("Creator"), SkString("Skia/DM"));
+
+    info.emplace_back(SkString("Keywords"),
+                      SkStringPrintf("Rasterizer:%s;", fRasterizer));
     doc->setMetadata(info, nullptr, nullptr);
     return draw_skdocument(src, doc.get(), dst);
 }