1 files changed, 30 insertions, 0 deletions
diff --git a/layout/base/MediaEmulationData.h b/layout/base/MediaEmulationData.h
new file mode 100644
index 0000000000..29d98d3f0b
--- /dev/null
+++ b/layout/base/MediaEmulationData.h
@@ -0,0 +1,30 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Common data for media query emulation by DevTools, hanging off nsPresContext
+ */
+
+#ifndef mozilla_MediaEmulationData_h
+#define mozilla_MediaEmulationData_h
+
+#include "nsAtom.h"
+#include "mozilla/Maybe.h"
+
+namespace mozilla {
+
+enum class StylePrefersColorScheme : uint8_t;
+
+struct MediaEmulationData final {
+  MediaEmulationData() = default;
+
+  RefPtr<nsAtom> mMedium;
+  float mDPPX = 0.0;
+  Maybe<StylePrefersColorScheme> mPrefersColorScheme;
+};
+
+}  // namespace mozilla
+
+#endif