Prevent tracking metrics for cases such as 204s and downloads.
More generally, ignore tracking metrics for navigations that result
in receiving a successful HTTP response but that don't commit.
The PageLoad UMA implementation currently tracks 204s and downloads as
aborts, as their net error status reported on NavigationHandle is
ERR_ABORTED. In reality these are just loads that terminated without
committing, so they should instead be ignored.
Note that the new tests fail when using browser-side navigation, and
are currently disabled there. See crbug.com/652767 for details.
BUG=651448
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation
Review-Url: https://codereview.chromium.org/2380773002
Cr-Commit-Position: refs/heads/master@{#423133}
6 files changed
