This patch implements a mechanism for more granular link URL permissions (filtering on scheme/host). This fixes the bug that allowed PDFs to have working links to any "chrome://" URLs.

BUG=528505,226927

Review URL: https://codereview.chromium.org/1362433002

Cr-Commit-Position: refs/heads/master@{#351705}
bool ChildProcessSecurityPolicyImpl::CanAccessDataForOrigin(int child_id,
                                                            const GURL& gurl) {
  base::AutoLock lock(lock_);
  SecurityStateMap::iterator state = security_state_.find(child_id);
  if (state == security_state_.end())
    return false;
  return state->second->CanAccessDataForOrigin(gurl);
}

bool ChildProcessSecurityPolicyImpl::CanAccessDataForOrigin(int child_id,
                                                            const GURL& gurl) {
  base::AutoLock lock(lock_);
  SecurityStateMap::iterator state = security_state_.find(child_id);
  if (state == security_state_.end())
    return false;
  return state->second->CanAccessDataForOrigin(gurl);
}
