DM: add --multiPage option

dm/DM.cpp

Index: dm/DM.cpp
diff --git a/dm/DM.cpp b/dm/DM.cpp
index e66584803dfdc953416c27bb52046a35f476af5d..1b9b86a1ef455dcc9f89226f4f1384fc919fc083 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -46,6 +46,9 @@ DEFINE_string(uninterestingHashesFile, "",
         "File containing a list of uninteresting hashes. If a result hashes to something in "
         "this list, no image is written for that result.");
 
+DEFINE_bool(multiPage, false, "For document-type backends, render the source"
+            " into multiple pages");
+
 __SK_FORCE_IMAGE_DECODER_LINKING;
 using namespace DM;
 
@@ -345,11 +348,11 @@ static Sink* create_sink(const char* tag) {
     if (FLAGS_cpu) {
         SINK("565",  RasterSink, kRGB_565_SkColorType);
         SINK("8888", RasterSink, kN32_SkColorType);
-        SINK("pdf",  PDFSink);
+        SINK("pdf", PDFSink, FLAGS_multiPage);
         SINK("skp",  SKPSink);
         SINK("svg",  SVGSink);
         SINK("null", NullSink);
-        SINK("xps",  XPSSink);
+        SINK("xps", XPSSink, FLAGS_multiPage);
     }
 #undef SINK
     return NULL;