Merged r21062, r21063 into 3.25 branch.

disable Object.observe

Adapt more test expectations

LOG=N
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/266643007

git-svn-id: https://v8.googlecode.com/svn/branches/3.25@21123 ce2b1a6d-e550-0410-aec6-3dcde31c8c00