s/popular/widely-used/

Author: jyasskin

index.bs

@@ -331,7 +331,7 @@ Before changing how a feature behaves,
 understand how websites are currently using it.
 
 Gaining a good understanding might require research,
-for example by adding metrics to a popular user agent
+for example by adding metrics to a widely-used user agent
 or by [searching the HTTP Archive](https://har.fyi/guides/getting-started/).
 Breaking content harms users,
 and the benefit of a change has to
@@ -352,7 +352,7 @@ Breakage is more likely to be acceptable if:
 * Only a tiny amount of existing content depend on the feature or behavior.
 * Only a tiny number of people see that content.
 * The content only appears in test cases or examples.
-* The content is already broken in most recent popular user agents.
+* The content is already broken in most recent widely-used user agents.
 * The content is not on the public web,
     but is instead found on internal sites
     with a controlled user environment.