Add some changes to TraceAnalyzer to improve analysis
* Tests which rely on being able to query for the end event in a pair
were not possible, partly because end events tend to be missing
information, and also because they did not reference their start
events
* Async event association can optionally be allowed for events which
span across process boundaries
BUG=None
Review-Url: https://codereview.chromium.org/2716023002
Cr-Commit-Position: refs/heads/master@{#455132}
(cherry picked from commit 83621ef58f633413145bd7093f16d56eb2c88103)
3 files changed
