Remove EventWrapper::Reset().

This simplifies the event wrapper which we've recently found issues in.
Also refactoring EndToEndTest.RespectsNetworkState to not depend on it.

BUG=
R=stefan@webrtc.org, tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/41939004

Cr-Original-Commit-Position: refs/heads/master@{#8366}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: d5ce2e63dfef7d3744f16ef23174aef23dd72e8f
14 files changed