Update to Chromium version 85.0.4183.0 (#782793)

- Windows: 10.0.19041 SDK is now required.
- macOS: 10.15.1 SDK (at least Xcode 11.2) is now required.
- Remove CefMediaSource::IsValid and CefMediaSink::IsValid which would
  always return true.

patch/patches/win_base_msvc_sandbox.patch

@@ -1,8 +1,8 @@
 diff --git base/values.cc base/values.cc
-index 4315dbc20684..91ce4e8e9ba1 100644
+index 5f5657935d92..8e4b33a1eb29 100644
 --- base/values.cc
 +++ base/values.cc
-@@ -25,20 +25,6 @@
+@@ -29,20 +29,6 @@
  
  namespace base {