Add histograms for tps65090 retries

We'd like some metrics about how many times we needed to retry turning
on tps65090 FETs at bootup and after suspend/resume.  This will let us
keep a handle on the workaround and also may provide early warning if
devices start nearing the maximum number of retries.

See http://crosreview.com/185026 for the ChromeOS CL that collects
these histograms.

NOTE that we primarily expect to see results on FET1, but collect
stats on all 7 FETs just in case one of them is having issues too.

BUG=338657

Review URL: https://codereview.chromium.org/135363008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249580 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249580
Exclude Plugins resources if enable_plugins==0.

BUG=326023

Review URL: https://codereview.chromium.org/149773003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249581 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249581
Hook up MediaScanManager to MediaFolderFinder and add top level results to preferences as galleries.

BUG=161119

Review URL: https://codereview.chromium.org/144283003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249582 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249582