base: Move renderer threads to the appropriate cpuset.

content/renderer/categorized_worker_pool.h

Index: content/renderer/categorized_worker_pool.h
diff --git a/content/renderer/categorized_worker_pool.h b/content/renderer/categorized_worker_pool.h
index 2f75f2183f24d0c145e55697f53c86470f371837..ffdfdc64c8b8130e3f4adb557d301e496534506c 100644
--- a/content/renderer/categorized_worker_pool.h
+++ b/content/renderer/categorized_worker_pool.h
@@ -69,6 +69,10 @@ class CONTENT_EXPORT CategorizedWorkerPool : public base::TaskRunner,
   // Create a new sequenced task graph runner.
   scoped_refptr<base::SequencedTaskRunner> CreateSequencedTaskRunner();
 
+  base::PlatformThreadId background_worker_thread_id() const {
+    return threads_.back()->tid();
+  }
+
  protected:
   ~CategorizedWorkerPool() override;