Ensure tests have an active task runner

chrome/browser/font_family_cache_unittest.cc

Index: chrome/browser/font_family_cache_unittest.cc
diff --git a/chrome/browser/font_family_cache_unittest.cc b/chrome/browser/font_family_cache_unittest.cc
index b7f8925deb27039218b382cf2984b5aa38fe9830..26cb3f88c47ae4a61b66ce5ca72697f9badbfe64 100644
--- a/chrome/browser/font_family_cache_unittest.cc
+++ b/chrome/browser/font_family_cache_unittest.cc
@@ -7,6 +7,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/test/base/testing_pref_service_syncable.h"
 #include "chrome/test/base/testing_profile.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
@@ -31,6 +32,7 @@ class TestingFontFamilyCache : public FontFamilyCache {
 
 // Tests that the cache is correctly set and cleared.
 TEST(FontFamilyCacheTest, Caching) {
+  content::TestBrowserThreadBundle thread_bundle_;
   TestingProfile profile;
   TestingFontFamilyCache cache(&profile);
   TestingPrefServiceSyncable* prefs = profile.GetTestingPrefService();