WebView: Add channel info for UMA

components/version_info/channel_android.h

+// Copyright 2017 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.
+
+#ifndef COMPONENTS_VERSION_INFO_CHANNEL_ANDROID_H_
+#define COMPONENTS_VERSION_INFO_CHANNEL_ANDROID_H_
+
+#include "components/version_info/channel.h"
+
+namespace version_info {
+
+// Determine channel based on Chrome's package name.
+Channel ChannelFromPackageName(const char* package_name);
+
+}  // namespace version_info
+
+#endif  // COMPONENTS_VERSION_INFO_CHANNEL_ANDROID_H_