image subsetting as part of the name instead of a separate source type

dm/DMSrcSink.cpp

Index: dm/DMSrcSink.cpp
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index cf72a3cacaf7bc9ff3250915152f3d5ac9df4101..64b2ec30a8a0b3fa18e750d2982cd0d1889fd04c 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -89,7 +89,13 @@ SkISize ImageSrc::size() const {
     return bitmap.dimensions();
 }
 
-Name ImageSrc::name() const { return SkOSPath::Basename(fPath.c_str()); }
+Name ImageSrc::name() const {
+    Name name = SkOSPath::Basename(fPath.c_str());
+    if (fSubsets > 0) {
+        name.appendf("-%d-subsets", fSubsets);
+    }
+    return name;
+}
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/