Soften the history.{push,replace}State throttling mechanism.

johnme@ suggests a better way to handle it; let's do that.

Bug: 786211
Change-Id: I446c70117451d2ef49ce13f5884ebb858d9ee392
Reviewed-on: https://chromium-review.googlesource.com/1161400
Commit-Queue: Chris Palmer <palmer@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580455}
2 files changed