Adapt /base/fuchsia to move-only thread options.

This change will let PlatformThread::Delegate::Options::delegate be a unique_ptr.
This CL was uploaded by git cl split.

Bug:1208166

R=ddorwin@chromium.org

Change-Id: Ide0d950cfc41b0be6a202195a920874ec78c7587
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2890389
Commit-Queue: Olivier Li <olivierli@chromium.org>
Auto-Submit: Olivier Li <olivierli@chromium.org>
Reviewed-by: David Dorwin <ddorwin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#881868}

base/fuchsia/intl_profile_watcher_unittest.cc

@@ -110,7 +110,7 @@ class FakePropertyProviderAsync {
           provider_request)
       : thread_("Property Provider Thread") {
     base::Thread::Options options(base::MessagePumpType::IO, 0);
-    CHECK(thread_.StartWithOptions(options));
+    CHECK(thread_.StartWithOptions(std::move(options)));
     property_provider_ = base::SequenceBound<FakePropertyProvider>(
         thread_.task_runner(), std::move(provider_request));
   }