Code: void AppCacheUpdateJob::OnDestructionImminent(AppCacheHost* host) {
   PendingMasters::iterator found =
       pending_master_entries_.find(host->pending_master_entry_url());
  DCHECK(found != pending_master_entries_.end());
   PendingHosts& hosts = found->second;
   PendingHosts::iterator it = std::find(hosts.begin(), hosts.end(), host);
  DCHECK(it != hosts.end());
   hosts.erase(it);
 }

Vulnerability Type: DoS 
CWE ID: 
Summary: Use-after-free vulnerability in the AppCache implementation in Google Chrome before 47.0.2526.73 allows remote attackers with renderer access to cause a denial of service or possibly have unspecified other impact by leveraging incorrect AppCacheUpdateJob behavior associated with duplicate cache selection.
Commit Message: Fix possible map::end() dereference in AppCacheUpdateJob triggered by a compromised renderer.

BUG=551044

Review URL: https://codereview.chromium.org/1418783005

Cr-Commit-Position: refs/heads/master@{#358815}