[Media Router] Adds a contextual menu item to remove the MR component action.

[Media Router] Adds a contextual menu item to remove the MR component action.

This adds a menu item to remove the MR component action from the toolbar.  It
sets a pref so this preference is respected across sessions.

The user can restore the action by reinstalling the Cast extension from the Web
Store.  (They may have to reload the Web Store page immediately after
installation to do so.)

BUG=576362
TESTED=Unit test, manually tested

Review URL: https://codereview.chromium.org/1612203002

Cr-Commit-Position: refs/heads/master@{#371629}
(cherry picked from commit 95cfa837a726c4400e025e826fcaddf1bfc751eb)

Committed: https://chromium.googlesource.com/chromium/src/+/d533aee7439c6cf2e01de5b540ad10fb9e79ab60

[mark a. foltz, 2016-02-09 00:18:49]

Description was changed from

==========
[Media Router] Adds a contextual menu item to remove the MR component action.

This adds a menu item to remove the MR component action from the toolbar.  It
sets a pref so this preference is respected across sessions.

The user can restore the action by reinstalling the Cast extension from the Web
Store.  (They may have to reload the Web Store page immediately after
installation to do so.)

BUG=576362
TESTED=Unit test, manually tested

Review URL: https://codereview.chromium.org/1612203002

Cr-Commit-Position: refs/heads/master@{#371629}
(cherry picked from commit 95cfa837a726c4400e025e826fcaddf1bfc751eb)
==========

to

==========
[Media Router] Adds a contextual menu item to remove the MR component action.

This adds a menu item to remove the MR component action from the toolbar.  It
sets a pref so this preference is respected across sessions.

The user can restore the action by reinstalling the Cast extension from the Web
Store.  (They may have to reload the Web Store page immediately after
installation to do so.)

BUG=576362
TESTED=Unit test, manually tested

Review URL: https://codereview.chromium.org/1612203002

Cr-Commit-Position: refs/heads/master@{#371629}
(cherry picked from commit 95cfa837a726c4400e025e826fcaddf1bfc751eb)

Committed:
https://chromium.googlesource.com/chromium/src/+/d533aee7439c6cf2e01de5b540ad...
==========

[mark a. foltz, 2016-02-09 00:18:50]

Committed patchset #1 (id:1) manually as
d533aee7439c6cf2e01de5b540ad10fb9e79ab60.