Add ongoing events to net-export log when logging starts
Update NetLogFileWriter::StartNetLog() to take a list of URLRequestContextGetters from which to retrieve ongoing events to add to the log.
Refactor FileNetLogObserver so log entries (specifically, entries for ongoing events) can be manually added from outside the class before it's attached to ChromeNetLog.
Add helper function to NetExportMessageHandler that retrieves a list of URLRequestContextGetters from which ongoing events are retrieved.
BUG=679021
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester
Review-Url: https://codereview.chromium.org/2698143004
Cr-Commit-Position: refs/heads/master@{#452993}
9 files changed
