Code: void Browser::SetWebContentsBlocked(content::WebContents* web_contents,
                                    bool blocked) {
  int index = tab_strip_model_->GetIndexOfWebContents(web_contents);
  if (index == TabStripModel::kNoTab) {
     return;
   }
   tab_strip_model_->SetTabBlocked(index, blocked);
 
   bool browser_active = BrowserList::GetInstance()->GetLastActive() == this;
  bool contents_is_active =
      tab_strip_model_->GetActiveWebContents() == web_contents;
  if (!blocked && contents_is_active && browser_active)
    web_contents->Focus();
}

Vulnerability Type: 
CWE ID: CWE-20
Summary: Incorrect dialog placement in Cast UI in Google Chrome prior to 70.0.3538.67 allowed a remote attacker to obscure the full screen warning via a crafted HTML page.
Commit Message: If a dialog is shown, drop fullscreen.

BUG=875066, 817809, 792876, 812769, 813815
TEST=included

Change-Id: Ic3d697fa3c4b01f5d7fea77391857177ada660db
Reviewed-on: https://chromium-review.googlesource.com/1185208
Reviewed-by: Sidney San Martín <sdy@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586418}