The problem here is estimating the marking step size for wrapper tracing. If the
steps are too small, we cannot keep up with the mutator creating new wrappers.
The result is an endless stream of incremental marking steps, alternating v8 and
wrappers tracing, without ever finalizing in a GC.

The mitigation here is to abort finding the fix point after 10 incremental
iterations.

A proper solution would track newly created wrappers on the blink side during
wrapper tracing. Will give this more thought after the holidays.

BUG=chromium:668164, chromium:468240

Review-Url: https://codereview.chromium.org/2592403002
Cr-Commit-Position: refs/heads/master@{#41923}