[Telemetry] Do close browser upon exceptions while creating

[Telemetry] Do close browser upon exceptions while creating

In some circumstances, the previous code would not close the
browser if an exception was raised _after_ the 
browser_backend started, but before the rest of the
constructor code was completed.

Also add a bit more logging to help keep track of each
browser instance started/closed.

BUG=chromium:749504
Review-Url: https://codereview.chromium.org/2992603003
Committed: https://chromium.googlesource.com/external/github.com/catapult-project/catapult/+/507c4af8b4edf1fae25e12236a860b1fa76592fd

[perezju, 2017-07-27 15:10:32]

perezju@chromium.org changed reviewers:
+ nednguyen@google.com

[nednguyen, 2017-07-27 15:11:33]

lgtm

[perezju, 2017-07-28 10:26:33]

Description was changed from

==========
[Telemetry] Extra logging when starting/closing browser

Keep track of each browser instance started/closed.

BUG=chromium:749504
==========

to

==========
[Telemetry] Do close browser upon exceptions while creating

In some circumstances, the previous code would not close the
browser if an exception was raised _after_ the 
browser_backend started, but before the rest of the
constructor code was completed.

Also add a bit more logging to help keep track of each
browser instance started/closed.

BUG=chromium:749504
==========

[perezju, 2017-07-28 10:27:53]

Ned, PTAL

Looking through the swarming logs I was able to figure out the root cause of the
issue; and added a simple fix for that here.

Left in the code for extra logging, since that might be helpful anyway if
similar issues crop up again.

https://codereview.chromium.org/2992603003/diff/20001/telemetry/telemetry/int...
File telemetry/telemetry/internal/browser/browser.py (right):

https://codereview.chromium.org/2992603003/diff/20001/telemetry/telemetry/int...
telemetry/telemetry/internal/browser/browser.py:60: self._LogBrowserInfo()
Exceptions raised during _browser_backend.Start() cause the browser to be closed
before continuing (due to code within browser_backend itself).

In the bug that triggered this issue, however, the exception was raised during
_LogBrowserInfo(); which just falls through the except block, calls
"WillCloseBrowser" but doesn't actually do anything to close the browser.

I was able to reproduce the issue by injecting a fake exception on
_LogBrowserInfo (a zombie browser instance is left open). And the issue is
indeed fixed by changing the "WillCloseBrowser" with plain "Close".

[nednguyen, 2017-07-28 10:43:11]

lgtm

[nednguyen, 2017-07-28 10:43:22]

On 2017/07/28 10:43:11, nednguyen wrote:
> lgtm

Thanks Juan!

[perezju, 2017-07-28 10:43:24]

The CQ bit was checked by perezju@chromium.org

[commit-bot: I haz the power, 2017-07-28 10:43:33]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-07-28 11:10:38]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1501238604913110,
"parent_rev": "7edadadddc70556b2a833617aa3c6147a87f2255", "commit_rev":
"507c4af8b4edf1fae25e12236a860b1fa76592fd"}

[commit-bot: I haz the power, 2017-07-28 11:10:41]

Description was changed from

==========
[Telemetry] Do close browser upon exceptions while creating

In some circumstances, the previous code would not close the
browser if an exception was raised _after_ the 
browser_backend started, but before the rest of the
constructor code was completed.

Also add a bit more logging to help keep track of each
browser instance started/closed.

BUG=chromium:749504
==========

to

==========
[Telemetry] Do close browser upon exceptions while creating

In some circumstances, the previous code would not close the
browser if an exception was raised _after_ the 
browser_backend started, but before the rest of the
constructor code was completed.

Also add a bit more logging to help keep track of each
browser instance started/closed.

BUG=chromium:749504

Review-Url: https://codereview.chromium.org/2992603003
Committed:
https://chromium.googlesource.com/external/github.com/catapult-project/catapu...
==========

[commit-bot: I haz the power, 2017-07-28 11:10:42]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/external/github.com/catapult-project/catapu...