Log captive portal status when an SSL interstitial is displayed.

When an SSL interstitial is displayed, we want to understand whether it's potentially caused by a captive portal or not. This CL records the following flags when the interstitial is closed:

1) Whether captive portal detection is enabled in Chrome (disabled on some OS).
2) Whether a captive portal probe result was received.
3) Whether the captive portal probe result returned no response, indicating a network or HTTP error or a non-HTTP captive portal login page.
4) Whether a captive portal was detected.

BUG=335933

Review URL: https://codereview.chromium.org/164843003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256063 0039d316-1c4b-4281-b951-d872f2087c98
Remove --prompt-for-extension-extensions switch. FeatureSwitch now can accept
NULL switch names, in which case it can't be controlled by the command line.

BUG=343979

Review URL: https://codereview.chromium.org/189993004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256064 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256063
Resubmit "Persist browseraction properties across restarts"

Resubmit CL after it broke tests. See comments for the fix.

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Persist browseraction properties across restarts
Persist browser action properties across restarts even if other properties are modified before the old ones are loaded. (Note: only properties which are NOT modified are persisted.)
BUG=348775

Review URL: https://codereview.chromium.org/191263002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256065 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256064
Remove NOTIFICATION_PROFILE_DESTROYED registration in PrerenderContents.

That logic got moved to the PrerenderManager.

BUG=none

Review URL: https://codereview.chromium.org/186773002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256066 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256066