Add missing generator dependencies in content/renderer/mus

Building //content/renderer/mus could fail due to transitive
dependencies on header generators pulled in via render_frame_impl.h
and render_thread_impl.h (building render_widget_mus_connection.cc
or compositor_mus_connection.cc could fail).

Unfortunately //content/renderer deps on //content/renderer/mus,
so there's no easy way to get these deps for free (cyclic dep).

BUG=655123

Review-Url: https://codereview.chromium.org/2461643002
Cr-Commit-Position: refs/heads/master@{#428428}
1 file changed