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
void RenderView::OnExecuteEditCommand(const std::string& name,
    const std::string& value) {
  if (!webview() || !webview()->focusedFrame())
    return;

  webview()->focusedFrame()->executeCommand(
      WebString::fromUTF8(name), WebString::fromUTF8(value));
}

void RenderView::OnExecuteEditCommand(const std::string& name,
    const std::string& value) {
  if (!webview() || !webview()->focusedFrame())
    return;

  webview()->focusedFrame()->executeCommand(
      WebString::fromUTF8(name), WebString::fromUTF8(value));
}
