Update to Chromium version 86.0.4240.0 (#800218)

- CefURLRequest::Create is no longer supported in the renderer process
  (see https://crbug.com/891872). Use CefFrame::CreateURLRequest instead.
- Mac platform definitions have been changed from `MACOSX` to `MAC`
  (see https://crbug.com/1105907) and related CMake macro names have
  been updated. The old `OS_MACOSX` define is still set in code and CMake
  for backwards compatibility.
- Linux ARM build is currently broken (see https://crbug.com/1123214).

libcef/browser/alloy/browser_platform_delegate_alloy.cc

@@ -222,7 +222,7 @@ void CefBrowserPlatformDelegateAlloy::SendCaptureLostEvent() {
     widget->LostCapture();
 }
 
-#if defined(OS_WIN) || (defined(OS_POSIX) && !defined(OS_MACOSX))
+#if defined(OS_WIN) || (defined(OS_POSIX) && !defined(OS_MAC))
 void CefBrowserPlatformDelegateAlloy::NotifyMoveOrResizeStarted() {
   if (!web_contents_)
     return;