Rename traits in //chromecast

This CL renames *_struct_traits.* to *_mojom_traits.* in //chromecast.
*_struct_traits.* => *_mojom_traits.*

Bug: 806965
Change-Id: I89c0503eb2f21d68ee10e0dfca459cd45eb790d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1699661
Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Miyoung Shin <myid.shin@igalia.com>
Cr-Commit-Position: refs/heads/master@{#677315}
3 files changed