add note about security and new subclasses

src/ports/SkGlobalInitialization_default.cpp

Index: src/ports/SkGlobalInitialization_default.cpp
diff --git a/src/ports/SkGlobalInitialization_default.cpp b/src/ports/SkGlobalInitialization_default.cpp
index a2b91b4a933537ce23f4f1d69dd4ff1d39af2a22..2b674ac7c578140fee133a72bd56fa3038628182 100644
--- a/src/ports/SkGlobalInitialization_default.cpp
+++ b/src/ports/SkGlobalInitialization_default.cpp
@@ -46,6 +46,14 @@
 #include "SkTileImageFilter.h"
 #include "SkXfermodeImageFilter.h"
 
+// Security note:
+//
+// As new subclasses are added here, they should be reviewed by chrome security before they

[Oliver Chang, 2016/02/03 23:53:58]

could you please also add a note to extend the filter fuzzer? and specify
chrome-security@google.com?

[reed1, 2016/02/04 00:03:16]

Done.

+// support deserializing cross-process.
+//
+// See SkReadBuffer::isCrossProcess() and SkPicture::PictureIOSecurityPrecautionsEnabled()
+//
+
 /*
  *  None of these are strictly "required" for Skia to operate.
  *