Add MediaPlayerRendererClient init safeguards

Speculative fix. This CL adds a clear failure path for many steps along
the InitScopedSurfaceRequest portion of the MediaPlayerRendererClient's
initialization sequence.

Bug: 919494
Change-Id: I6f7277b16c9902727785384bc85285f51df7d647
Reviewed-on: https://chromium-review.googlesource.com/c/1399449
Reviewed-by: Frank Liberato <liberato@chromium.org>
Commit-Queue: Thomas Guilbert <tguilbert@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620600}
2 files changed