Adding a new component, Previews.

components/previews/previews_experiments.h

+// Copyright 2016 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_PREVIEWS_PREVIEWS_EXPERIMENTS_H_
+#define COMPONENTS_PREVIEWS_PREVIEWS_EXPERIMENTS_H_
+
+namespace previews {
+
+// Returns true if any client-side previews experiment is active.
+bool IsIncludedInClientSidePreviewsExperimentsFieldTrial();
+
+// Returns true if the field trial that should enable offline pages for
+// prohibitvely slow networks is active.
+bool IsOfflinePreviewsEnabled();
+
+}  // namespace previews
+
+#endif  // COMPONENTS_PREVIEWS_PREVIEWS_EXPERIMENTS_H_