Move channel-related (Chrome-specific) global state out of Feature.

chrome/common/extensions/features/feature_channel.cc

+// Copyright 2013 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 "chrome/common/extensions/features/feature_channel.h"
+
+using chrome::VersionInfo;
+
+namespace {
+
+const VersionInfo::Channel kDefaultChannel = VersionInfo::CHANNEL_STABLE;
+VersionInfo::Channel g_current_channel = kDefaultChannel;
+
+}  // namespace
+
+namespace extensions {
+
+VersionInfo::Channel GetCurrentChannel() {
+  return g_current_channel;
+}
+
+void SetCurrentChannel(VersionInfo::Channel channel) {
+  g_current_channel = channel;
+}
+
+VersionInfo::Channel GetDefaultChannel() {
+  return kDefaultChannel;
+}
+
+}  // namespace extensions