Retry proxies which were cached as bad before giving up.

This morphs ProxyList::RemoveBadProxies() into ProxyList::DeprioritizeBadProxies(), such that "bad proxies" are moved to the end of the fallback list rather than removed alltogether.

BUG=31983
TEST=ProxyListTest.DeprioritizeBadProxies

Review URL: http://codereview.chromium.org/542029

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@36054 0039d316-1c4b-4281-b951-d872f2087c98
8 files changed