[DevTools] Enable "auto attach to sub frames" by default

[DevTools] Enable "auto attach to sub frames" by default

Also made "Inspect Element" open DevTools for main page now.

BUG=652783
Review-Url: https://codereview.chromium.org/2859063002
Cr-Commit-Position: refs/heads/master@{#469568}
Committed: https://chromium.googlesource.com/chromium/src/+/a2a5081b066eb679783fc84c7fb4b11480ffb696

[dgozman, 2017-05-03 23:16:04]

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

[dgozman, 2017-05-03 23:16:26]

dgozman@chromium.org changed reviewers:
+ pfeldman@chromium.org

[dgozman, 2017-05-03 23:16:26]

Could you please take a look?

[commit-bot: I haz the power, 2017-05-03 23:16:43]

Dry run: 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, 2017-05-04 00:48:32]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-04 00:48:32]

Dry run: This issue passed the CQ dry run.

[pfeldman, 2017-05-04 22:31:21]

lgtm

[dgozman, 2017-05-05 00:16:08]

The CQ bit was checked by dgozman@chromium.org

[commit-bot: I haz the power, 2017-05-05 00:16:54]

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, 2017-05-05 01:49:03]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493943368854680, "parent_rev":
"27cd342cd4d1adf5690be47b7c80b83122b1d9bd", "commit_rev":
"a2a5081b066eb679783fc84c7fb4b11480ffb696"}

[commit-bot: I haz the power, 2017-05-05 01:49:15]

Description was changed from

==========
[DevTools] Enable "auto attach to sub frames" by default

Also made "Inspect Element" open DevTools for main page now.

BUG=652783
==========

to

==========
[DevTools] Enable "auto attach to sub frames" by default

Also made "Inspect Element" open DevTools for main page now.

BUG=652783

Review-Url: https://codereview.chromium.org/2859063002
Cr-Commit-Position: refs/heads/master@{#469568}
Committed:
https://chromium.googlesource.com/chromium/src/+/a2a5081b066eb679783fc84c7fb4...
==========

[commit-bot: I haz the power, 2017-05-05 01:49:16]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/a2a5081b066eb679783fc84c7fb4...

[wOxxOm, 2017-08-15 17:10:41]

Doesn't seem to auto-attach to a chrome-extension:// iframe added within a
normal web page, PTAL https://crbug.com/755515