Move blimp_layer_tree_settings.h/cc to client.

These aren't needed by the engine, so I'm moving this to blimp/client
from blimp/common to fix an engine build error.

BUG=527655

Review URL: https://codereview.chromium.org/1420883006

Cr-Commit-Position: refs/heads/master@{#358721}
8 files changed