Limit recomputing of gpu driver bug workarounds to chromeos and android

I don't feel other platforms will benefit, rather, they could possibly lose some.

For example, on Linux CollectContextGraphicsInfo does not do PCI scan for vendor/device IDs (sandbox issues, efficiency issues, etc).  Therefore, multiple-gpu entries will be skipped, as we only pass the primary gpu info from browser process to gpu process.

BUG=306231
TEST=
R=piman@chromium.org

Review URL: https://codereview.chromium.org/110923004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240623 0039d316-1c4b-4281-b951-d872f2087c98
Blink roll 163798:163831

http://build.chromium.org/f/chromium/perf/dashboard/ui/changelog_blink.html?url=/trunk&range=163799:163831&mode=html
TBR=
BUG=

Review URL: https://codereview.chromium.org/114753003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240624 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240625 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240625
Add a custom button to user pods on the login/lock screen.

This button is beside the password field and is shown through the
chrome.screenlockPrivate API.

BUG=320156
TEST=manual

Review URL: https://codereview.chromium.org/111013004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240626 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240626