[Chromecast] Handle device scale factor correctly

chromecast/browser/cast_web_contents_user_data.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 CHROMECAST_BROWSER_CAST_WEB_CONTENTS_USER_DATA_H_
+#define CHROMECAST_BROWSER_CAST_WEB_CONTENTS_USER_DATA_H_
+
+#include "base/macros.h"
+#include "base/supports_user_data.h"
+
+namespace chromecast {
+namespace shell {
+
+class CastWebContentsUserData : public base::SupportsUserData::Data {
+ public:
+  static void* UserDataKey() {
+    return &key_;
+  }
+
+  explicit CastWebContentsUserData(int resolution_height);
+
+  int resolution_height() const { return resolution_height_; }
+
+ private:
+  static int key_;
+
+  const int resolution_height_;
+
+  DISALLOW_COPY_AND_ASSIGN(CastWebContentsUserData);
+};
+
+}  // namespace shell
+}  // namespace chromecast
+
+#endif  // CHROMECAST_BROWSER_CAST_WEB_CONTENTS_USER_DATA_H_