[oilpan]: Don't sweep while in safepoint.

Related to the test failures seen in the worker-data-view-test.html test I think this will fix the issue. Basically postpone the sweep until after we have left the safepoint. I am still testing/trying to reproduce.

R=ager@chromium.org, erik.corry@gmail.com, haraken@chromium.org, oilpan-reviews@chromium.org, sof@opera.com, tkent@chromium.org, vegorov@chromium.org, zerny@chromium.org
BUG=

Review URL: https://codereview.chromium.org/351253002

git-svn-id: svn://svn.chromium.org/blink/trunk@177124 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add [TypeChecking=Interface] on various methods in Document.idl

This adds type checks on some Node arguments in the generated bindings
code, and lets us drop the corresponding manual null checks and exception
throwing code in the implementations.

The type of exception thrown changes from DOMException (NOT_SUPPORTED_ERR)
to TypeError as a side-effect. This matches the Web IDL specification.

Review URL: https://codereview.chromium.org/360463005

git-svn-id: svn://svn.chromium.org/blink/trunk@177125 bbb929c8-8fbe-4397-9dbb-9b2b20218538