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* This is done as preparation for a subsequent refactoring of the
  safety check WebUi code. It moves the source of truth for the
  safety check parent status from the JS side to the C++ side. This
  removes some of the interdependencies of parent to children (and
  vice versa), and allows for a subsequent splitting of parent and
  children into individual parts on the WebUi side.
* This CL is part 1 of the change, which adds logic to handle the parent
  state in C++ and the communication from C++ to JS.

Bug: 1015841
Change-Id: I3716457964377ae3177884d5987281fd2c470a2a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2144022Reviewed-by: Esmael Elmoslimany <aee@chromium.org>
Commit-Queue: Rainhard Findling <rainhard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759692}