Store USB device permissions in website settings.

chrome/browser/permissions/chooser_context_base.h

+// Copyright 2015 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_PERMISSIONS_CHOOSER_CONTEXT_BASE_H_
+#define CHROME_BROWSER_PERMISSIONS_CHOOSER_CONTEXT_BASE_H_
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+#include "components/content_settings/core/common/content_settings_types.h"
+#include "components/keyed_service/core/keyed_service.h"
+
+namespace base {
+class DictionaryValue;
+class Value;
+}
+
+class GURL;
+class HostContentSettingsMap;
+class Profile;
+
+// This is the base class for services that manage any type of permission that
+// is granted through a chooser-style UI instead of a simple allow/deny prompt.
+// Subclasses must define the structure of the objects that are stored.
+class ChooserContextBase : public KeyedService {
+ public:
+  ChooserContextBase(Profile* profile,
+                     ContentSettingsType permission_type,
+                     ContentSettingsType chooser_type);
+  ~ChooserContextBase() override;
+
+  // Returns the list of objects that |requesting_origin| has been granted
+  // permission to access when embedded within |embedding_origin|.
+  ScopedVector<base::DictionaryValue> GetPreviouslyChosenObjects(

[mlamouri (slow - plz ping), 2015/11/06 15:22:46]

nit: GetGrantedObjects()

+      const GURL& requesting_origin,
+      const GURL& embedding_origin);
+
+  // Grants |requesting_origin| access to |object| when embedded within
+  // |embedding_origin| by writing it into |host_content_settings_map_|.
+  void GrantObjectPermission(const GURL& requesting_origin,
+                             const GURL& embedding_origin,
+                             scoped_ptr<base::DictionaryValue> object);
+
+  // Revokes |requesting_origin|'s permission to access |object| when embedded
+  // within |embedding_origin|.
+  void RevokeObjectPermission(const GURL& requesting_origin,
+                              const GURL& embedding_origin,
+                              const base::DictionaryValue& object);
+
+  // Validates the structure of an object read from
+  // |host_content_settings_map_|.
+  virtual bool IsValidObject(const base::DictionaryValue& object) = 0;
+
+ private:
+  scoped_ptr<base::DictionaryValue> GetWebsiteSetting(
+      const GURL& requesting_origin,
+      const GURL& embedding_origin);
+  void SetWebsiteSetting(const GURL& requesting_origin,
+                         const GURL& embedding_origin,
+                         scoped_ptr<base::Value> value);
+
+  HostContentSettingsMap* const host_content_settings_map_;
+  const ContentSettingsType permission_type_;

[mlamouri (slow - plz ping), 2015/11/06 15:22:46]

nit: could you rename this |guard_content_setting_type_|

+  const ContentSettingsType chooser_type_;

[mlamouri (slow - plz ping), 2015/11/06 15:22:46]

nit: could you rename this |objects_content_setting_type_| or whatever name that
will make it clear it's about saving individual object permissions.

+};
+
+#endif  // CHROME_BROWSER_PERMISSIONS_CHOOSER_CONTEXT_BASE_H_