The content API design explicitly mentions that we shouldn't have const interfaces in the public API: https://www.chromium.org/developers/content-module/content-api. The reasoning is that "For interfaces implemented by the embedder, we can't make assumptions about what the embedder needs to implement it. For interfaces implemented by content, the implementation details doesn't have to be exposed."
This isn't a rule we've been enforcing, which causes confusion for both developers and reviewers touching code in that API surface.
We should fix the existing use cases, and start enforcing that rule with a PRESUBMIT rule.
Comment 1 by bugdroid1@chromium.org
, Nov 29