Resource Timing: Do not report subsequent navigations within subframes

We only want to record resource timing for the load that was initiated
by parent document. We filter out subsequent navigations for <iframe>,
but we should do it for other types of subframes too.

Bug: 780312
Change-Id: I3a7b9e1a365c99e24bb8dac190e88c7099fc3da5
Reviewed-on: https://chromium-review.googlesource.com/750487
Reviewed-by: Nate Chapin <japhet@chromium.org>
Commit-Queue: Kunihiko Sakamoto <ksakamoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513665}
PluginSet& PluginsPendingDispose() {
  DEFINE_STATIC_LOCAL(PluginSet, set, ());
  return set;
}

PluginSet& PluginsPendingDispose() {
  DEFINE_STATIC_LOCAL(PluginSet, set, ());
  return set;
}
