Fix theme colors not updating when navigating back/from the NTP.

Fix theme colors not updating when navigating back/from the NTP.

This moves to better centralize and isoalte the theme color
tracking.  Tab will now be in charge of determining when to
notify its observers about theme color changes.

The previous problem was that TabWebContentsObserver and Tab
were notifying observers and it was a mismatch of who was tracking
the theme colors (in particular with the addition of native pages).

This also removes the additional handling that was being done
in WebContents.java/WebContentsImpl.java as that did not match
the native behavior.  The need for non-transparent colors should
be isolated to the chrome component where we are choosing how to
apply them.

BUG=614006
Committed: https://crrev.com/e754522e92e66cbef3662d433467fa96958511ac
Cr-Commit-Position: refs/heads/master@{#396054}

[Ted C, 2016-05-24 23:13:18]

tedchoc@chromium.org changed reviewers:
+ yusufo@chromium.org

[Ted C, 2016-05-24 23:13:19]

PTAL

[Yusuf, 2016-05-25 00:11:11]

lgtm

[Ted C, 2016-05-25 00:17:20]

The CQ bit was checked by tedchoc@chromium.org

[Ted C, 2016-05-25 00:17:22]

The patchset sent to the CQ was uploaded after l-g-t-m from yusufo@chromium.org
Link to the patchset: https://codereview.chromium.org/2014433002/#ps40001
(title: "Rebased")

[commit-bot: I haz the power, 2016-05-25 00:18:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2014433002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2014433002/40001

[commit-bot: I haz the power, 2016-05-25 03:20:05]

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

[commit-bot: I haz the power, 2016-05-25 03:20:06]

Try jobs failed on following builders:
  linux_android_rel_ng on tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_androi...)

[Ted C, 2016-05-25 22:26:16]

The CQ bit was checked by tedchoc@chromium.org

[Ted C, 2016-05-25 22:26:17]

The patchset sent to the CQ was uploaded after l-g-t-m from yusufo@chromium.org
Link to the patchset: https://codereview.chromium.org/2014433002/#ps60001
(title: "Fix tests")

[commit-bot: I haz the power, 2016-05-25 22:27:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2014433002/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2014433002/60001

[commit-bot: I haz the power, 2016-05-26 00:34:35]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2016-05-26 00:36:07]

Description was changed from

==========
Fix theme colors not updating when navigating back/from the NTP.

This moves to better centralize and isoalte the theme color
tracking.  Tab will now be in charge of determining when to
notify its observers about theme color changes.

The previous problem was that TabWebContentsObserver and Tab
were notifying observers and it was a mismatch of who was tracking
the theme colors (in particular with the addition of native pages).

This also removes the additional handling that was being done
in WebContents.java/WebContentsImpl.java as that did not match
the native behavior.  The need for non-transparent colors should
be isolated to the chrome component where we are choosing how to
apply them.

BUG=614006
==========

to

==========
Fix theme colors not updating when navigating back/from the NTP.

This moves to better centralize and isoalte the theme color
tracking.  Tab will now be in charge of determining when to
notify its observers about theme color changes.

The previous problem was that TabWebContentsObserver and Tab
were notifying observers and it was a mismatch of who was tracking
the theme colors (in particular with the addition of native pages).

This also removes the additional handling that was being done
in WebContents.java/WebContentsImpl.java as that did not match
the native behavior.  The need for non-transparent colors should
be isolated to the chrome component where we are choosing how to
apply them.

BUG=614006

Committed: https://crrev.com/e754522e92e66cbef3662d433467fa96958511ac
Cr-Commit-Position: refs/heads/master@{#396054}
==========

[commit-bot: I haz the power, 2016-05-26 00:36:08]

Patchset 4 (id:??) landed as
https://crrev.com/e754522e92e66cbef3662d433467fa96958511ac
Cr-Commit-Position: refs/heads/master@{#396054}