Adds a hide button to the desktop capture notification bar.
The new button is used to minimize the notification to the taskbar (or Mac Dock). It's designed to look like a link to differentiate itself from the "stop sharing" button, which is an action on desktop capture.

BUG=316731

Review URL: https://codereview.chromium.org/195283003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256851 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256851
Move extensions-related files to using //components/keyed_service.

This CL removes the usage of //components/browser_context_keyed_service
from:
- //chrome/browser/extensions
- //extensions

It was constructed using the following:
- move_source_file.py --already_moved
- mffr.py
- git cl format

BUG=351704
TBR=yoz

Review URL: https://codereview.chromium.org/197413002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256853 0039d316-1c4b-4281-b951-d872f2087c98
Updates comment for PlatformChannelPair::PassClientHandle

BUG=none
TEST=none
TBR=viettrungluu@chromium.org
R=viettrungluu@chromium.org

Review URL: https://codereview.chromium.org/196383007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256854 0039d316-1c4b-4281-b951-d872f2087c98
override new virtual onWritePixels instead of deprecated writePixels

BUG=

Review URL: https://codereview.chromium.org/199033002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256855 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256854
SVN changes up to revision 256855