Revert 247967 "Appcache::OnCorruptionDetected handling. The gene..."

AppCacheDiskCacheTest.DisableWithEntriesOpen started failing on both Android Tests and Android Tests (dbg) with this change.

http://build.chromium.org/p/chromium.linux/builders/Android%20Tests%20%28dbg%29/builds/18225/
http://build.chromium.org/p/chromium.linux/builders/Android%20Tests/builds/11615/

> Appcache::OnCorruptionDetected handling. The general idea is to delete everything and start over (reinitialize) if we notice corruption on disk. The is some pre-existing code to perform the reinitialization function, but that was only used in a more narrow case where the disk cache could not have been open. With the changes in this CL, reinitialization can be triggered pretty much at any time.
>  
> TBR=jam
> BUG=318544
> 
> Review URL: https://codereview.chromium.org/137493003

TBR=michaeln@chromium.org

Review URL: https://codereview.chromium.org/150683002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248014 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248014