Use Value in ChooserContextBase

This change refactors ChooserContextBase, its subclasses, and uses of
the class to use base::Value instead of base::DictionaryValue.

Bug: 920288
Change-Id: I53fc103fbcd38045ed23ce23b07a45fbbec32553
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1575038
Reviewed-by: Theresa <twellington@chromium.org>
Reviewed-by: Ben Wells <benwells@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Ovidio de Jesús Ruiz-Henríquez <odejesush@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653169}
17 files changed