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).

include/internal/cef_types.h

@@ -39,7 +39,7 @@
 // Bring in platform-specific definitions.
 #if defined(OS_WIN)
 #include "include/internal/cef_types_win.h"
-#elif defined(OS_MACOSX)
+#elif defined(OS_MAC)
 #include "include/internal/cef_types_mac.h"
 #elif defined(OS_LINUX)
 #include "include/internal/cef_types_linux.h"

include/internal/cef_types_mac.h

@@ -33,7 +33,7 @@
 
 #include "include/base/cef_build.h"
 
-#if defined(OS_MACOSX)
+#if defined(OS_MAC)
 #include "include/internal/cef_string.h"
 
 // Handle types.
@@ -137,6 +137,6 @@ typedef struct _cef_window_info_t {
 }
 #endif
 
-#endif  // OS_MACOSX
+#endif  // OS_MAC
 
 #endif  // CEF_INCLUDE_INTERNAL_CEF_TYPES_MAC_H_