In preparation for our support library, we should remove imports of android.webkit.* from all non-glue layer classes (aka chromium layer).
One class we use all over is android.webkit.ValueCallback.
We need to keep this in the glue layer, since it's used as part of WebView APIs. However, we can remove its use in implementation-only code and replace it with Callback.java.
We should do the conversion from ValueCallback <-> Callback in the glue layer.
Comment 1 by gsennton@chromium.org
, Sep 13 2017