Revert of Validate vector lengths in ImageHostMsg_DidDownloadImage (https://codereview.chromium.org/133123006/)

Reason for revert:
Discussion required on whether to call ReceivedBadMessage to kill the renderer or not

Original issue's description:
> Validate vector lengths in ImageHostMsg_DidDownloadImage
> 
> BUG=333038
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=245618

TBR=sky@chromium.org,cevans@chromium.org,jln@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=333038

Review URL: https://codereview.chromium.org/131493009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245661 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245661