Record SkCanvas::flush().

We can record multiple frames in an .skp by recording SkCanvas::flush().
This should make SkPictures, SkLiteDL, and .skp files all record flush().

Change-Id: I6cf6e0e4ef993530d9f92fa168a53702ffce7d5e
Reviewed-on: https://skia-review.googlesource.com/34081
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
diff --git a/src/core/SkRecorder.cpp b/src/core/SkRecorder.cpp
index 1eeef53..3d53e93 100644
--- a/src/core/SkRecorder.cpp
+++ b/src/core/SkRecorder.cpp
@@ -346,6 +346,10 @@
     APPEND(DrawAnnotation, rect, SkString(key), sk_ref_sp(value));
 }
 
+void SkRecorder::onFlush() {
+    APPEND(Flush);
+}
+
 void SkRecorder::willSave() {
     APPEND(Save);
 }