Remove WorkerFetchContextHolder

Keeping scoped_refptr<WebWorkerFetchContext> in WorkerFetchContextHolder
cause WebWorkerFetchContext destruction on the main thread, because
WorkerFetchContextHolder is destructed on the main thread.

To avoid this, this CL passes WebWorkerFetchContext via
GlobalScopeCreationParams to WorkerOrWorkletGlobalScope.

This CL doesn't change the behavior.

Bug: 880027
Change-Id: Idab91d31cafdb33b264662c5f1bef126d93ba9f3
Reviewed-on: https://chromium-review.googlesource.com/c/1198891
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606649}
27 files changed