add --write option to dump_record

BUG=skia:

Review URL: https://codereview.chromium.org/1459823003
diff --git a/tools/dump_record.cpp b/tools/dump_record.cpp
index 49781bf..1b5f1dc 100644
--- a/tools/dump_record.cpp
+++ b/tools/dump_record.cpp
@@ -9,6 +9,8 @@
 #include "LazyDecodeBitmap.h"
 #include "SkCommandLineFlags.h"
 #include "SkPicture.h"
+#include "SkPictureRecorder.h"
+#include "SkRecordDraw.h"
 #include "SkRecordOpts.h"
 #include "SkRecorder.h"
 #include "SkStream.h"
@@ -19,6 +21,7 @@
 DEFINE_bool2(optimize, O, false, "Run SkRecordOptimize before dumping.");
 DEFINE_int32(tile, 1000000000, "Simulated tile size.");
 DEFINE_bool(timeWithCommand, false, "If true, print time next to command, else in first column.");
+DEFINE_string2(write, w, "", "Write the (optimized) picture to the named file.");
 
 static void dump(const char* name, int w, int h, const SkRecord& record) {
     SkBitmap bitmap;
@@ -32,7 +35,6 @@
     DumpRecord(record, &canvas, FLAGS_timeWithCommand);
 }
 
-
 int tool_main(int argc, char** argv);
 int tool_main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
@@ -65,6 +67,20 @@
         }
 
         dump(FLAGS_skps[i], w, h, record);
+
+        if (FLAGS_write.count() > 0) {
+            SkPictureRecorder r;
+            SkRecordDraw(record,
+                         r.beginRecording(SkRect::MakeIWH(w, h)),
+                         nullptr,
+                         nullptr,
+                         0,
+                         nullptr,
+                         nullptr);
+            SkAutoTUnref<SkPicture> dst(r.endRecording());
+            SkFILEWStream ostream(FLAGS_write[0]);
+            dst->serialize(&ostream);
+        }
     }
 
     return 0;