Add flag to call SkRecordOptimize on new pictures.

src/core/SkPicture.cpp

Index: src/core/SkPicture.cpp
diff --git a/src/core/SkPicture.cpp b/src/core/SkPicture.cpp
index 5b9921024ef5525d60897b5d203ddf72fb5e6bd4..c99939703c6ae8ce3614fb139400b189bb416695 100644
--- a/src/core/SkPicture.cpp
+++ b/src/core/SkPicture.cpp
@@ -639,9 +639,11 @@ uint32_t SkPicture::uniqueID() const {
     return fUniqueID;
 }
 
+
 static SkRecord* optimized(SkRecord* r) {
-    // TODO(mtklein): try this after SkRecord has stuck
-    //SkRecordOptimize(r);
+#ifdef SK_PICTURE_OPTIMIZE_SK_RECORD
+    SkRecordOptimize(r);
+#endif
     return r;
 }