Enable features API for content shell and webview

base/feature_list_unittest.cc

 // Copyright 2015 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/feature_list.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <utility>
@@ skipping 406 matching lines @@
 
   EXPECT_FALSE(FieldTrialList::IsTrialActive("T1"));
   EXPECT_FALSE(FeatureList::IsEnabled(kFeatureOffByDefault));
   EXPECT_TRUE(FieldTrialList::IsTrialActive("T1"));
 
   EXPECT_FALSE(FieldTrialList::IsTrialActive("T2"));
   EXPECT_TRUE(FeatureList::IsEnabled(kFeatureOnByDefault));
   EXPECT_TRUE(FieldTrialList::IsTrialActive("T2"));
 }
 
+TEST_F(FeatureListTest, InitializeInstance) {
+  ClearFeatureListInstance();
+
+  scoped_ptr<base::FeatureList> feature_list(new base::FeatureList);
+  FeatureList::SetInstance(std::move(feature_list));
+  EXPECT_TRUE(FeatureList::IsEnabled(kFeatureOnByDefault));
+  EXPECT_FALSE(FeatureList::IsEnabled(kFeatureOffByDefault));
+
+  // Initialize from command line if we haven't yet.
+  FeatureList::InitializeInstance("", kFeatureOnByDefaultName);
+  EXPECT_FALSE(FeatureList::IsEnabled(kFeatureOnByDefault));
+  EXPECT_FALSE(FeatureList::IsEnabled(kFeatureOffByDefault));
+
+  // Do not initialize from commandline if we have already.
+  FeatureList::InitializeInstance(kFeatureOffByDefaultName, "");
+  EXPECT_FALSE(FeatureList::IsEnabled(kFeatureOnByDefault));
+  EXPECT_FALSE(FeatureList::IsEnabled(kFeatureOffByDefault));
+}
+
 }  // namespace base