Experiment with redirecting all BrowserThreads (but UI/IO) to TaskScheduler

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 740231cc36035f558b240f7fc81762f8288db728..85f9f6e0bdfd8da8ca5d35cb8a26a4f82fc34915 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -3305,6 +3305,12 @@ ChromeContentBrowserClient::GetMemoryCoordinatorDelegate() {
   return memory::ChromeMemoryCoordinatorDelegate::Create();
 }
 
+bool ChromeContentBrowserClient::
+    RedirectNonUINonIOBrowserThreadsToTaskScheduler() {
+  return variations::GetVariationParamValue(
+             "BrowserScheduler", "RedirectNonUINonIOBrowserThreads") == "true";
+}
+
 #if BUILDFLAG(ENABLE_MEDIA_REMOTING)
 void ChromeContentBrowserClient::CreateMediaRemoter(
     content::RenderFrameHost* render_frame_host,