[merge-m57] Forward declare blink::mojom::EngagementLevel in Document.h

[merge-m57] Forward declare blink::mojom::EngagementLevel in Document.h

Similar to https://codereview.chromium.org/2677543003/ but with
presubmit fixes.

r439726 added a #include for site_engagement.mojom-blink.h to Document.h
without adding the necessary public_deps to build files. We can avoid
adding more build dependencies to Document.h with a forward declare, so
do that.

Sheriff landing TBR to fix Pri-0 builder issues.

BUG=687707, 692813
Also bugs: 688353, 682986
TBR=mgiuca@chromium.org

Review-Url: https://codereview.chromium.org/2677003002
Cr-Commit-Position: refs/heads/master@{#448224}
(cherry picked from commit f8ca4752e20998b51f7bc1cac9c651db80302bed)

Review-Url: https://codereview.chromium.org/2698853002 .
Cr-Commit-Position: refs/branch-heads/2987@{#534}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed: https://chromium.googlesource.com/chromium/src/+/d6184b6f1fd91a6ff4422993b2d0e2994fec50c7

[tapted, 2017-02-16 00:56:55]

Description was changed from

==========
[merge-m57] Forward declare blink::mojom::EngagementLevel in Document.h

Similar to https://codereview.chromium.org/2677543003/ but with
presubmit fixes.

r439726 added a #include for site_engagement.mojom-blink.h to Document.h
without adding the necessary public_deps to build files. We can avoid
adding more build dependencies to Document.h with a forward declare, so
do that.

Sheriff landing TBR to fix Pri-0 builder issues.

BUG=687707, 692813
Also bugs: 688353, 682986
TBR=mgiuca@chromium.org

Review-Url: https://codereview.chromium.org/2677003002
Cr-Commit-Position: refs/heads/master@{#448224}
(cherry picked from commit f8ca4752e20998b51f7bc1cac9c651db80302bed)
==========

to

==========
[merge-m57] Forward declare blink::mojom::EngagementLevel in Document.h

Similar to https://codereview.chromium.org/2677543003/ but with
presubmit fixes.

r439726 added a #include for site_engagement.mojom-blink.h to Document.h
without adding the necessary public_deps to build files. We can avoid
adding more build dependencies to Document.h with a forward declare, so
do that.

Sheriff landing TBR to fix Pri-0 builder issues.

BUG=687707, 692813
Also bugs: 688353, 682986
TBR=mgiuca@chromium.org

Review-Url: https://codereview.chromium.org/2677003002
Cr-Commit-Position: refs/heads/master@{#448224}
(cherry picked from commit f8ca4752e20998b51f7bc1cac9c651db80302bed)

Review-Url: https://codereview.chromium.org/2698853002 .
Cr-Commit-Position: refs/branch-heads/2987@{#534}
Cr-Branched-From:
ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed:
https://chromium.googlesource.com/chromium/src/+/d6184b6f1fd91a6ff4422993b2d0...
==========

[tapted, 2017-02-16 00:56:57]

Committed patchset #1 (id:1) manually as
d6184b6f1fd91a6ff4422993b2d0e2994fec50c7.