Add a ScopedFeatureList class for testing and start using it.

base/test/test_suite.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/test/test_suite.h"
 
 #include <memory>
 
 #include "base/at_exit.h"
 #include "base/base_paths.h"
@@ skipping 293 matching lines @@
     debug::WaitForDebugger(60, true);
   }
 #endif
 
   // Set up a FeatureList instance, so that code using that API will not hit a
   // 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 cleared in Shutdown() via
   // ClearInstanceForTesting().
   created_feature_list_ =
       FeatureList::InitializeInstance(std::string(), std::string());
+  printf("initing the instance\n");

[Ilya Sherman, 2016/08/09 01:06:57]

Plz revert ;)

[Alexei Svitkine (slow), 2016/08/09 01:26:16]

Done.

 
 #if defined(OS_IOS)
   InitIOSTestMessageLoop();
 #endif  // OS_IOS
 
 #if defined(OS_ANDROID)
   InitAndroidTest();
 #else
   // Initialize logging.
   FilePath exe;
@@ skipping 59 matching lines @@
 
 void TestSuite::Shutdown() {
   base::debug::StopProfiling();
 
   // Clear the FeatureList that was created by Initialize().
   if (created_feature_list_)
     FeatureList::ClearInstanceForTesting();
 }
 
 }  // namespace base