WebStateListObserver methods have default implementation.

WebStateListObserver methods have default implementation.

As most of the observer are only interested in a sub-set of the
events and to mirror the Objective-C API (WebStateListObserving)
that marks all methods as optional, add empty implementation to
WebStateList methods.

BUG=687207
Review-Url: https://codereview.chromium.org/2708733003
Cr-Commit-Position: refs/heads/master@{#452516}
Committed: https://chromium.googlesource.com/chromium/src/+/073e0546fc624d92d47dcf4778fdce5a2391f835

[sdefresne, 2017-02-21 15:49:58]

sdefresne@chromium.org changed reviewers:
+ marq@chromium.org, rohitrao@chromium.org

[sdefresne, 2017-02-21 15:49:59]

To whoever would be the faster to review.

[marq (ping after 24h), 2017-02-21 16:19:48]

lgtm

[sdefresne, 2017-02-23 15:33:22]

The CQ bit was checked by sdefresne@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-02-23 15:33:45]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[sdefresne, 2017-02-23 16:29:49]

The CQ bit was unchecked by sdefresne@chromium.org

[sdefresne, 2017-02-23 16:29:52]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2017-02-23 16:30:03]

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, 2017-02-23 16:34:35]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1487867392610170, "parent_rev":
"edef4982396f33e6038ba37df5f200921bc63f79", "commit_rev":
"073e0546fc624d92d47dcf4778fdce5a2391f835"}

[commit-bot: I haz the power, 2017-02-23 16:35:07]

Description was changed from

==========
WebStateListObserver methods have default implementation.

As most of the observer are only interested in a sub-set of the
events and to mirror the Objective-C API (WebStateListObserving)
that marks all methods as optional, add empty implementation to
WebStateList methods.

BUG=687207
==========

to

==========
WebStateListObserver methods have default implementation.

As most of the observer are only interested in a sub-set of the
events and to mirror the Objective-C API (WebStateListObserving)
that marks all methods as optional, add empty implementation to
WebStateList methods.

BUG=687207

Review-Url: https://codereview.chromium.org/2708733003
Cr-Commit-Position: refs/heads/master@{#452516}
Committed:
https://chromium.googlesource.com/chromium/src/+/073e0546fc624d92d47dcf4778fd...
==========

[commit-bot: I haz the power, 2017-02-23 16:35:10]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/073e0546fc624d92d47dcf4778fd...