[sensors] Add Permission guard to the generic sensor apis.

chrome/browser/sensor/sensor_permission_context.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 CHROME_BROWSER_SENSOR_SENSOR_PERMISSION_CONTEXT_H_
+#define CHROME_BROWSER_SENSOR_SENSOR_PERMISSION_CONTEXT_H_
+
+#include "base/macros.h"
+#include "chrome/browser/permissions/permission_context_base.h"
+
+class GURL;
+class PermissionRequestID;
+
+class SensorPermissionContext : public PermissionContextBase {
+ public:
+  explicit SensorPermissionContext(Profile* profile);
+  ~SensorPermissionContext() override;
+
+ private:
+  // PermissionContextBase:
+  void UpdateTabContext(const PermissionRequestID& id,
+                        const GURL& requesting_frame,
+                        bool allowed) override;
+  bool IsRestrictedToSecureOrigins() const override;
+
+  DISALLOW_COPY_AND_ASSIGN(SensorPermissionContext);
+};
+
+#endif  // CHROME_BROWSER_SENSOR_SENSOR_PERMISSION_CONTEXT_H_