GitLab

In a future CL, we will be removing the "Cast" button in the dialog
and enabling the user to start casting just by clicking on a sink. This
CL is in preparation for that.

Currently, the source list only shows sources supported by the currently
selected sink. This CL makes the list show all the sources. When a source
is selected, we disable buttons for sinks that do not support the source.

The visual design for disabled sinks is TBD; the icon/text are greyed out
for now.

Bug: 872509

Change-Id: I5ba719d08dd85e2b8915da22d0a2b22988b4f384
Reviewed-on: https://chromium-review.googlesource.com/1166341
Commit-Queue: Takumi Fujimoto <takumif@chromium.org>
Reviewed-by: Derek Cheng <imcheng@chromium.org>
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583492}