Remove ContextLifecycleObserver from WorkerPerformance

Remove ContextLifecycleObserver from WorkerPerformance

WorkerPerformance is inheriting from ContextLifecycleObserver
only to implement EventTarget::getExecutionContext().
WorkerPerformance should just hold a strong member to ExecutionContext.

BUG=610176
Committed: https://crrev.com/3ed589328bdfb4cdfe160bbf6e42dc6b9dd33d16
Cr-Commit-Position: refs/heads/master@{#436940}

[haraken, 2016-12-07 11:06:37]

haraken@chromium.org changed reviewers:
+ sigbjornf@opera.com

[haraken, 2016-12-07 11:06:38]

PTAL

Easy one.

[sof, 2016-12-07 12:03:01]

lgtm

[haraken, 2016-12-07 12:12:46]

The CQ bit was checked by haraken@chromium.org

[commit-bot: I haz the power, 2016-12-07 12:12:58]

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, 2016-12-07 14:15:01]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1481112766415260, "parent_rev":
"a2977e2463f386ca35737d6c082610c7ccbd8d34", "commit_rev":
"8449496869a607aa7088d4a7d72e1be35220318f"}

[commit-bot: I haz the power, 2016-12-07 14:15:28]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-07 14:17:20]

Description was changed from

==========
Remove ContextLifecycleObserver from WorkerPerformance

WorkerPerformance is inheriting from ContextLifecycleObserver
only to implement EventTarget::getExecutionContext().
WorkerPerformance should just hold a strong member to ExecutionContext.

BUG=610176
==========

to

==========
Remove ContextLifecycleObserver from WorkerPerformance

WorkerPerformance is inheriting from ContextLifecycleObserver
only to implement EventTarget::getExecutionContext().
WorkerPerformance should just hold a strong member to ExecutionContext.

BUG=610176

Committed: https://crrev.com/3ed589328bdfb4cdfe160bbf6e42dc6b9dd33d16
Cr-Commit-Position: refs/heads/master@{#436940}
==========

[commit-bot: I haz the power, 2016-12-07 14:17:21]

Patchset 1 (id:??) landed as
https://crrev.com/3ed589328bdfb4cdfe160bbf6e42dc6b9dd33d16
Cr-Commit-Position: refs/heads/master@{#436940}