Revert Change ServiceManagerConnectionImpl to run service request handlers on the IO thread

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 aa0fee8c2f08847b4a5645c8e42ef9096e57355b..be95e08ec19e7a490dd6d22e32c935676b3199c0 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -3232,7 +3232,6 @@ void ChromeContentBrowserClient::RegisterInProcessServices(
     content::ServiceInfo info;
     info.factory = base::Bind(&ash_util::CreateEmbeddedAshService,
                               base::ThreadTaskRunnerHandle::Get());
-    info.task_runner = base::ThreadTaskRunnerHandle::Get();
     services->insert(std::make_pair(ash::mojom::kServiceName, info));
   }
 #endif  // OS_CHROMEOS