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).

tools/cefbuilds/cef_html_builder.py

@@ -126,7 +126,7 @@ class cef_html_builder:
         'linux64': 'Linux 64-bit',
         'linuxarm': 'Linux ARM',
         'linuxarm64': 'Linux ARM64',
-        'macosx64': 'Mac OS X 64-bit',
+        'macosx64': 'MacOS 64-bit',
         'windows32': 'Windows 32-bit',
         'windows64': 'Windows 64-bit'
     }[platform]