AppCache: Run a quick integrity check on the sqlite database when opening. If the test fails, delete the appcache directory and start afresh.

NOTRY=true
TBR=sky
BUG=318544

Review URL: https://codereview.chromium.org/104593010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240937 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240937
[Refactor] Removes usage of ProfileManager::GetDefaultProfileOrOffTheRecord() from help related code

BUG=322682
TEST=None

Review URL: https://codereview.chromium.org/112023008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240939 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240939