Reland "Put resource timing events on a timer when triggered by a cache hit."

Stash state from the Resource* synchronously, so that it doesn't still have to be alive when the timer fires.

BUG=327065
TEST=http/tests/misc/cache-hit-resource-timing-buffer-full-crash.html

BUG=

Review URL: https://codereview.chromium.org/138953002

git-svn-id: svn://svn.chromium.org/blink/trunk@165691 bbb929c8-8fbe-4397-9dbb-9b2b20218538