Update to Chromium version 88.0.4324.0 (#827102)

- Mac: Xcode 12.2 and the MacOS 11.0 SDK are now required for building.
- MacOS 10.10 (Yosemite) is no longer supported (see https://crbug.com/1126056).
- Flash is no longer supported (see https://www.chromium.org/flash-roadmap).

include/base/cef_logging.h

@@ -554,12 +554,7 @@ const LogSeverity LOG_DCHECK = LOG_INFO;
 #define DCHECK_GE(val1, val2) DCHECK_OP(GE, >=, val1, val2)
 #define DCHECK_GT(val1, val2) DCHECK_OP(GT, >, val1, val2)
 
-#if defined(NDEBUG) && defined(OS_CHROMEOS)
-#define NOTREACHED() \
-  LOG(ERROR) << "NOTREACHED() hit in " << __FUNCTION__ << ". "
-#else
 #define NOTREACHED() DCHECK(false)
-#endif
 
 // Redefine the standard assert to use our nice log files
 #undef assert