[scheduling] Change RAILMode tracing category

Move RAILMode from Info to Default so it's not disabled by default.

Change-Id: Ib302aa70bb4f87e579d8c925eebfc43744f8bd0d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2397719
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809238}

third_party/blink/renderer/platform/scheduler/main_thread/main_thread_scheduler_impl.h

@@ -849,7 +849,7 @@ class PLATFORM_EXPORT MainThreadSchedulerImpl
         longest_jank_free_task_duration;
     TraceableCounter<int, TracingCategoryName::kInfo>
         renderer_pause_count;  // Renderer is paused if non-zero.
-    TraceableState<RAILMode, TracingCategoryName::kInfo>
+    TraceableState<RAILMode, TracingCategoryName::kTopLevel>
         rail_mode_for_tracing;  // Don't use except for tracing.
     TraceableState<bool, TracingCategoryName::kTopLevel> renderer_hidden;
     base::Optional<base::ScopedSampleMetadata> renderer_hidden_metadata;