DM::NullSink

dm/DMSrcSink.h

Index: dm/DMSrcSink.h
diff --git a/dm/DMSrcSink.h b/dm/DMSrcSink.h
index e163a24253f88e4ed58b2ca956588b0b16c96c24..4dcd280bb35dcefa2f785043f466e744fff60a92 100644
--- a/dm/DMSrcSink.h
+++ b/dm/DMSrcSink.h
@@ -8,6 +8,7 @@
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkGPipe.h"
+#include "SkNullCanvas.h"
 #include "SkPicture.h"
 #include "gm.h"
 
@@ -175,6 +176,16 @@ private:
     SkAutoTDelete<Sink>         fSink;
 };
 
+class NullSink : public Sink {
+public:
+    Error draw(const Src& src, SkBitmap*, SkWStream* out) const SK_OVERRIDE {
+        (void)out->writeText("0\n");

[mtklein, 2015/01/29 20:00:12]

Is this so we don't try to encode an empty bitmap?

Sounds like we want the check to go from:

if (stream.len() > 0) {
  writeStream
} else {
  writeBitmap
}

to

if (stream.len() > 0) {
  writeStream
}
if (bitmap.sensible()) {
  writeBitmap
}

We don't really want to write any file for NullSink, do we?

[hal.canary, 2015/01/30 18:43:24]

Done.

+        return src.draw(SkCreateNullCanvas());
+    }
+    int enclave() const SK_OVERRIDE { return kAnyThread_Enclave; }
+    const char* fileExtension() const SK_OVERRIDE { return "null"; }

[mtklein, 2015/01/29 20:00:12]

or even, ""?

[hal.canary, 2015/01/30 18:43:24]

Done.

+};
+
 }  // namespace DM
 
 #endif//DMSrcSink_DEFINED