Speculative revert 170900 "Make most decoded resource logic private to Memor..."

http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Mac10.6/builds/26089

> Make most decoded resource logic private to MemoryCache
> 
> BUG=
> 
> Review URL: https://codereview.chromium.org/222413005

TBR=japhet@chromium.org

Review URL: https://codereview.chromium.org/225023016

git-svn-id: svn://svn.chromium.org/blink/trunk@170905 bbb929c8-8fbe-4397-9dbb-9b2b20218538