Fix a crash when closing an off-screen browser with no references (issue #1121).

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1500 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

libcef/browser/browser_host_impl.cc

@@ -1543,6 +1543,10 @@ void CefBrowserHostImpl::CloseContents(content::WebContents* source) {
       // via the platform window destruction mechanism.
       PlatformCloseWindow();
     } else {
+      // Keep a reference to the browser while it's in the process of being
+      // destroyed.
+      CefRefPtr<CefBrowserHostImpl> browser(this);
+
       // No window exists. Destroy the browser immediately.
       DestroyBrowser();
       if (!IsWindowRenderingDisabled()) {