[Sheriff] Revert "Let SetEntropySource() fail if called after V8::Initialize()."

This reverts commit 16889 for breaking the webkit tests.

TBR=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/23530071

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16896 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Remove duplicated heap allocation functions.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/24261012

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16897 ce2b1a6d-e550-0410-aec6-3dcde31c8c00