Version 3.25.30 (based on bleeding_edge revision r20316)

NativeContext::map_cache reference should be strong in heap snapshots (Chromium issue 357060).

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@20318 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge remote-tracking branch 'upstream/trunk' into trunk