GitLab

Move ReadableStream to ReadableStreamWrapper. Make ReadableStream be an
interface which can have multiple implementations. Make
ReadableStreamWrapper implement the ReadableStream interface, and be
delegated to by the ReadableStream static methods.

Deprecate ReadableStreamOperations as it won't work with the new
implementation.

BUG=902633

Change-Id: Idcc8ae62e787e5696698f13229d19c91ca7a7e74
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1494394Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#637651}