We could potentially filter out the file, but before we dive into what that would look like, I'd like to understand the problem a little bit more. Could you expand on why the matches aren't useful? 

lighthouse-background is a compiled javascript file;built in a separate projected and rolled into Blink regularly.
What makes it particularly annoying is that within it is a slightly older version of some files from third_party/WebKit/Source/devtools/front_end/. 

Since it shows up in search, the team working on devtools finds lighthouse-background in the search results, when it is definitely never the intended result. As an example, look at this search: https://cs.chromium.org/search/?q=NetworkManager%5C.fromTarget&sq=package:chromium&type=cs

The top result looks about right, but if you click on it, you'll not only be waiting for ~30 seconds for the page to render, but it's old code.

I will +1 this.

Since Javascript currently does not support ability to click into code to navigate much of our team has developed some muscle memory to filter out different code from different areas to find what we need.

My muscle memory is something like:

"f:devtools -f:out"

Otherwise we get results form all kinds of places that are not at all relevant. Lighthouse recently caused us to now also get results from it, which means we now need:

"f:devtools -f:out -f:lighthouse"

A good example of this is if I was looking for all calls of:
"requestHeadersText"

See what happens if you search with:
"-f:out f:devtools requestHeadersText"