This means the network is slow, and Chrome is replacing a web font (loaded with a
@font-face rule) with a local fallback.
By default, the text rendered with a web font is invisible until the font is downloaded (“flash of invisible text”). With this change, the user on a slow network could start reading right when the content is loaded instead of looking into the empty page for several seconds.
- Related Chrome issue: https://bugs.chromium.org/p/chromium/issues/detail?id=578029. (A change enabling this behavior for 3G connections landed in September; this should be the reason you got the message.)
- Related source code: https://chromium.googlesource.com/chromium/src/third_party/+/master/WebKit/Source/core/css/RemoteFontFaceSource.cpp#74