DM: add --rtree.

BUG=
R=epoger@google.com

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/51243003

git-svn-id: http://skia.googlecode.com/svn/trunk@12033 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/dm/DMUtil.cpp b/dm/DMUtil.cpp
index a227ca8..d521484 100644
--- a/dm/DMUtil.cpp
+++ b/dm/DMUtil.cpp
@@ -23,10 +23,10 @@
     return expectations.match(digest);
 }
 
-void RecordPicture(skiagm::GM* gm, SkPicture* picture) {
+void RecordPicture(skiagm::GM* gm, SkPicture* picture, uint32_t recordFlags) {
     SkCanvas* canvas = picture->beginRecording(SkScalarCeilToInt(gm->width()),
                                                SkScalarCeilToInt(gm->height()),
-                                               0 /*flags*/);
+                                               recordFlags);
     canvas->concat(gm->getInitialTransform());
     gm->draw(canvas);
     canvas->flush();