AutoFill: Release the cached frame when we receive the frameDestroyed() message
from WebKit.

BUG=48857
TEST=none

Review URL: http://codereview.chromium.org/3173005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@55789 0039d316-1c4b-4281-b951-d872f2087c98
static void GetRedirectChain(WebDataSource* ds, std::vector<GURL>* result) {
  WebVector<WebURL> urls;
  ds->redirectChain(urls);
  result->reserve(urls.size());
  for (size_t i = 0; i < urls.size(); ++i)
    result->push_back(urls[i]);
}

static void GetRedirectChain(WebDataSource* ds, std::vector<GURL>* result) {
  WebVector<WebURL> urls;
  ds->redirectChain(urls);
  result->reserve(urls.size());
  for (size_t i = 0; i < urls.size(); ++i)
    result->push_back(urls[i]);
}
