Separate JSON functions from DMWriteTask.

dm/DMJsonWriter.h

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef DMJsonWriter_DEFINED
+#define DMJsonWriter_DEFINED
+
+#include "SkString.h"
+
+namespace DM {
+
+class JsonWriter {
+public:
+    struct GmData {

[mtklein, 2014/11/04 13:53:23]

This guy can be a little more general than GmData.  E.g, we can and do fill it
with results from SKPs.  Perhaps, BitmapResult?

[scroggo, 2014/11/04 15:01:52]

Done.

+        SkString name;            // E.g. "ninepatch-stretch", "desk-gws_skp"
+        SkString config;          //      "gpu", "8888"
+        SkString mode;            //      "direct", "default-tilegrid", "pipe"
+        SkString sourceType;      //      "GM", "SKP"
+        SkString md5;             // In ASCII, so 32 bytes long.
+    };
+
+    static void AddGmData(GmData data);

[mtklein, 2014/11/04 13:53:23]

Can you add a note like // All methods thread-safe. ?

[scroggo, 2014/11/04 15:01:52]

Done.

+
+    static void DumpJson();
+};
+
+} // namespace DM
+#endif // DMJsonWriter_DEFINED