GitLab

This CL fixes memory leaks caused by not calling disposePerContextData on
ScriptState.

BUG=524875

Review URL: https://codereview.chromium.org/1314333002

git-svn-id: svn://svn.chromium.org/blink/trunk@201299 bbb929c8-8fbe-4397-9dbb-9b2b20218538