Update to Chromium version 74.0.3729.0 (#638880)

- Windows: 10.0.17763.0 SDK is now required.
- Mac: 10.13 SDK is now required.
- Removed CefRequestContext::ResolveHostCached which is no longer supported by Chromium.

libcef/common/request_impl.h

@@ -29,7 +29,7 @@ class UploadElement;
 class UploadElementReader;
 class URLFetcher;
 class URLRequest;
-};  // namespace net
+}  // namespace net
 
 namespace blink {
 class WebURLRequest;