If JavaScript shows a dialog, cause the page to lose fullscreen.

BUG=670135, 550017, 726761, 728276

Review-Url: https://codereview.chromium.org/2906133004
Cr-Commit-Position: refs/heads/master@{#478884}
std::vector<WebContentsImpl*> WebContentsImpl::GetInnerWebContents() {
  if (browser_plugin_embedder_) {
    std::vector<WebContentsImpl*> inner_contents;
    GetBrowserContext()->GetGuestManager()->ForEachGuest(
        this, base::Bind(&GetInnerWebContentsHelper, &inner_contents));
    return inner_contents;
  }

  return node_.inner_web_contents();
}

std::vector<WebContentsImpl*> WebContentsImpl::GetInnerWebContents() {
  if (browser_plugin_embedder_) {
    std::vector<WebContentsImpl*> inner_contents;
    GetBrowserContext()->GetGuestManager()->ForEachGuest(
        this, base::Bind(&GetInnerWebContentsHelper, &inner_contents));
    return inner_contents;
  }

  return node_.inner_web_contents();
}
