This has been happening for about a week.

To reproduce:

1) Load
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h?type=cs&q=NGFragmentBuilder&sq=package:chromium&l=19

2) Type NGFragm

3) Select first NGFragment.h match

4) Now you've been taken to:
https://cs.chromium.org/webrtc/src/third_party/WebKit/Source/core/layout/ng/ng_fragment.h?type=cs&sq=package:chromium&q=NGFragme&l=16

Notice webrtc inside the code path. 

The page that is loaded displays source, but cross-reference and override layers are missing.

If I manually change the url, and remove webrtc everything works:
https://cs.chromium.org/src/third_party/WebKit/Source/core/layout/ng/ng_fragment.h?type=cs&sq=package:chromium&q=NGFragme&l=16