[Sync::USS] Inline ClientTagBasedModelTypeProcessor::IsModelReadyOrError

This CL inlines ClientTagBasedModelTypeProcessor::IsModelReadyOrError()
for better readability especially it has one single caller.

Change-Id: I28e379dc1e7ad705f1c39fad6d6567089af658f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1583745
Commit-Queue: Mohamed Amir Yosef <mamir@chromium.org>
Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653997}
2 files changed