[Media Router] Sync state when MR extension is (re)connected to MR.

[Media Router] Sync state when MR extension is (re)connected to MR.

The extension might have become out of sync with MediaRouter due to one
of few reasons:
(1) The extension crashed and lost unpersisted changes.
(2) The extension was updated; temporary data is cleared.
(3) The extension has an unforseen bug which causes temporary data to be
    persisted incorrectly on suspension.

The number of calls made for the state sync should be relatively small
(< 10), and quite inexpensive since the extension is already up. Note
that the calls must be (and are) idempotent; the extension will no-op
if the query / observer being registered already exists.

Note that the existing mDNS activation call is also considered part of
state sync.

BUG=717325
Review-Url: https://codereview.chromium.org/2855473004
Cr-Commit-Position: refs/heads/master@{#469067}
(cherry picked from commit adb75ff0ecd96123cfeab63e9ab2bfc368e29f05)

Review-Url: https://codereview.chromium.org/2857393005 .
Cr-Commit-Position: refs/branch-heads/3071@{#407}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/ee03b79650fe4de5f74e0979ee8e6eec900f2d2b

[imcheng, 2017-05-04 21:30:35]

Description was changed from

==========
[Media Router] Sync state when MR extension is (re)connected to MR.

The extension might have become out of sync with MediaRouter due to one
of few reasons:
(1) The extension crashed and lost unpersisted changes.
(2) The extension was updated; temporary data is cleared.
(3) The extension has an unforseen bug which causes temporary data to be
    persisted incorrectly on suspension.

The number of calls made for the state sync should be relatively small
(< 10), and quite inexpensive since the extension is already up. Note
that the calls must be (and are) idempotent; the extension will no-op
if the query / observer being registered already exists.

Note that the existing mDNS activation call is also considered part of
state sync.

BUG=717325

Review-Url: https://codereview.chromium.org/2855473004
Cr-Commit-Position: refs/heads/master@{#469067}
(cherry picked from commit adb75ff0ecd96123cfeab63e9ab2bfc368e29f05)
==========

to

==========
[Media Router] Sync state when MR extension is (re)connected to MR.

The extension might have become out of sync with MediaRouter due to one
of few reasons:
(1) The extension crashed and lost unpersisted changes.
(2) The extension was updated; temporary data is cleared.
(3) The extension has an unforseen bug which causes temporary data to be
    persisted incorrectly on suspension.

The number of calls made for the state sync should be relatively small
(< 10), and quite inexpensive since the extension is already up. Note
that the calls must be (and are) idempotent; the extension will no-op
if the query / observer being registered already exists.

Note that the existing mDNS activation call is also considered part of
state sync.

BUG=717325

Review-Url: https://codereview.chromium.org/2855473004
Cr-Commit-Position: refs/heads/master@{#469067}
(cherry picked from commit adb75ff0ecd96123cfeab63e9ab2bfc368e29f05)

Review-Url: https://codereview.chromium.org/2857393005 .
Cr-Commit-Position: refs/branch-heads/3071@{#407}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/ee03b79650fe4de5f74e0979ee8e...
==========

[imcheng, 2017-05-04 21:30:37]

Committed patchset #1 (id:1) manually as
ee03b79650fe4de5f74e0979ee8e6eec900f2d2b.