Changes to support using base/feature_list.h from gin/.

base/test/test_suite.cc

Index: base/test/test_suite.cc
diff --git a/base/test/test_suite.cc b/base/test/test_suite.cc
index 74bd9ddf7bd5bd238fb4997630c7dc5bdf51370b..486320ebad4416399b5c2faae086b84e10b91e9e 100644
--- a/base/test/test_suite.cc
+++ b/base/test/test_suite.cc
@@ -212,6 +212,12 @@ int TestSuite::Run() {
   mac::ScopedNSAutoreleasePool scoped_pool;
 #endif
 
+  // Set up a FeatureList instance, so that code using that API will not hit a

[Paweł Hajdan Jr., 2016/04/04 16:45:17]

While you're here: could you move this code to Initialize/Shutdown?

Consider this optional, especially if that hits any errors or other yak shave.

However, if just moving it works, I'd recommend we do that.

[Alexei Svitkine (slow), 2016/04/04 20:01:55]

Seems to work. Done.

+  // an error that it's not set. If a FeatureList was created in this way (i.e.
+  // one didn't exist previously), it will be ClearInstanceForTesting() below.
+  const bool created_feature_list =
+      FeatureList::InitializeInstance(std::string(), std::string());
+
   Initialize();
   std::string client_func =
       CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
@@ -224,14 +230,11 @@ int TestSuite::Run() {
   test_listener_ios::RegisterTestEndListener();
 #endif
 
-  // Set up a FeatureList instance, so that code using that API will not hit a
-  // an error that it's not set. Cleared by ClearInstanceForTesting() below.
-  base::FeatureList::SetInstance(make_scoped_ptr(new base::FeatureList));
-
   int result = RUN_ALL_TESTS();
 
   // Clear the FeatureList that was registered above.
-  FeatureList::ClearInstanceForTesting();
+  if (created_feature_list)
+    FeatureList::ClearInstanceForTesting();
 
 #if defined(OS_MACOSX)
   // This MUST happen before Shutdown() since Shutdown() tears down