Test Keeping NaCl plugins used in app background pages alive when active.

(Re-landing with fixes from https://codereview.chromium.org/111563006/ )

Activity in Native Client plugins results in IPC messages
sent to the BrowserPpapiHostImpl and routed to call
extensions::ProcessManager::KeepaliveImpulse.

Testing patch, builds on implementation:
https://codereview.chromium.org/61063003/

Design doc:
https://docs.google.com/a/chromium.org/document/d/1mI0lS1rfAf-BAGLmWAEcWy37Xq9dOvgfMx8OqeUMXts/edit#

BUG=298339

No change to mseaborn owned file since last LGTM:
TBR=mseaborn@chromium.org

Review URL: https://codereview.chromium.org/112663007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243021 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243021
Blink roll 164476:164479

http://build.chromium.org/f/chromium/perf/dashboard/ui/changelog_blink.html?url=/trunk&range=164477:164479&mode=html
TBR=
BUG=

Review URL: https://codereview.chromium.org/115173008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243022 0039d316-1c4b-4281-b951-d872f2087c98
[OSX] Adjust BlueLabelButton rendering.

BlueLabelButton used to make room for the drop shadow by leaving a 1px
border around the entire button. Since the drop shadow is only drawn
below the button, that left extraneous whitespace that made adjusting
other buttons to the same width/height difficult.

Changed to instead leave a one pixel sliver below the button only, and
added adjustment to ensure visual appearance of BlueLabelButtons stayed
exactly the same.

R=thakis@chromium.org
BUG=none

Review URL: https://codereview.chromium.org/116193005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243023 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243024 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243024