Pass user session type to extension feature checks

extensions/common/features/feature_session_type.h

Index: extensions/common/features/feature_session_type.h
diff --git a/extensions/common/features/feature_session_type.h b/extensions/common/features/feature_session_type.h
new file mode 100644
index 0000000000000000000000000000000000000000..51811c68d8cbe3a5348ae33c859741733025423c
--- /dev/null
+++ b/extensions/common/features/feature_session_type.h
@@ -0,0 +1,47 @@
+// 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 EXTENSIONS_COMMON_FEATURES_FEATURE_SESSION_TYPE_H_
+#define EXTENSIONS_COMMON_FEATURES_FEATURE_SESSION_TYPE_H_
+
+#include "base/macros.h"
+
+namespace extensions {
+
+// Classes of session types to which features can be restricted in feature
+// files. The session type describes session based on the type of user that is
+// active in the current session.
+enum FeatureSessionType {
+  FEATURE_SESSION_TYPE_UNSPECIFIED,
+  // Regular session, i.e. non kiosk app.
+  FEATURE_SESSION_TYPE_REGULAR,

[rkc, 2016/08/17 23:07:24]

We will definitely want to add more states later, so let's keep this more
specific.
UNSPECIFIED - means currently any state that we don't handle, like maybe login
screen, tests, etc.

REGULAR should instead be LOGGED_IN_USER.
We can later add things like LOGIN_SCREEN, EPHEMERAL_USER, etc.

Nit: s/UNSPECIFIED/UNKNOWN

[tbarzic, 2016/08/18 01:05:33]

Done. Kept REGULAR user per offline discussion.

+  // Kiosk app session.
+  FEATURE_SESSION_TYPE_KIOSK,
+  // Helper for determining max enum value - not used as a real type.
+  FEATURE_SESSION_TYPE_MAX = FEATURE_SESSION_TYPE_KIOSK
+};
+
+// Gets the current session type as seen by the Feature system.
+FeatureSessionType GetCurrentFeatureSessionType();
+
+// Sets the current session type as seen by the Feature system. In the browser
+// process this should be extensions::util::GetCurrentSessionType(), and in
+// the renderer this will need to come from an IPC.
+void SetCurrentFeatureSessionType(FeatureSessionType session_type);
+
+// Scoped session type setter. Use for tests.
+class ScopedCurrentFeatureSessionType {
+ public:
+  explicit ScopedCurrentFeatureSessionType(FeatureSessionType session_type);
+  ~ScopedCurrentFeatureSessionType();
+
+ private:
+  FeatureSessionType original_session_type_{FEATURE_SESSION_TYPE_UNSPECIFIED};
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedCurrentFeatureSessionType);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_COMMON_FEATURES_FEATURE_SESSION_TYPE_H_