More aggressive IO asserts in content_browsertests.

content/public/test/content_browser_test_utils.cc

Index: content/public/test/content_browser_test_utils.cc
diff --git a/content/public/test/content_browser_test_utils.cc b/content/public/test/content_browser_test_utils.cc
index b77a2724d31722b87715645e4307b8cb69094134..971bff095b1164b4520a7be070e7e256ee65d73e 100644
--- a/content/public/test/content_browser_test_utils.cc
+++ b/content/public/test/content_browser_test_utils.cc
@@ -10,6 +10,7 @@
 #include "base/run_loop.h"
 #include "base/strings/pattern.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/threading/thread_restrictions.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/web_contents.h"
@@ -25,9 +26,11 @@ namespace content {
 
 base::FilePath GetTestFilePath(const char* dir, const char* file) {
   base::FilePath path;
+  base::ThreadRestrictions::ScopedAllowIO allow_io_for_path_service;
   PathService::Get(DIR_TEST_DATA, &path);
-  return path.Append(base::FilePath().AppendASCII(dir).Append(
-      base::FilePath().AppendASCII(file)));
+  if (dir)
+    path = path.AppendASCII(dir);
+  return path.AppendASCII(file);
 }
 
 GURL GetTestUrl(const char* dir, const char* file) {