[Extensions] Move Feature channel code into //extensions

chrome/common/extensions/manifest_tests/extension_manifests_background_unittest.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 <memory>
 
 #include "base/command_line.h"
 #include "base/values.h"
-#include "chrome/common/extensions/features/feature_channel.h"
 #include "chrome/common/extensions/manifest_tests/chrome_manifest_test.h"
 #include "components/version_info/version_info.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/error_utils.h"
 #include "extensions/common/extension.h"
+#include "extensions/common/features/feature_channel.h"
 #include "extensions/common/manifest_constants.h"
 #include "extensions/common/manifest_handlers/background_info.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace extensions {
 
 namespace errors = manifest_errors;
 namespace keys = manifest_keys;
 
 class ExtensionManifestBackgroundTest : public ChromeManifestTest {
@@ skipping 111 matching lines @@
   std::string error;
   std::vector<InstallWarning> warnings;
   ManifestHandler::ValidateExtension(extension.get(), &error, &warnings);
   // The key 'background.persistent' is not supported for packaged apps.
   EXPECT_EQ(1U, warnings.size());
   EXPECT_EQ(errors::kBackgroundPersistentInvalidForPlatformApps,
             warnings[0].message);
 }
 
 }  // namespace extensions