Add API to set render process preferences

atom/browser/render_process_preferences.h

@@ -0,0 +1,61 @@
+// Copyright (c) 2016 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_BROWSER_RENDER_PROCESS_PREFERENCES_H_
+#define ATOM_BROWSER_RENDER_PROCESS_PREFERENCES_H_
+
+#include <memory>
+#include <unordered_map>
+
+#include "base/callback.h"
+#include "base/values.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+
+namespace content {
+class RenderProcessHost;
+}
+
+namespace atom {
+
+// Sets user preferences for render processes.
+class RenderProcessPreferences : public content::NotificationObserver {
+ public:
+  using Predicate = base::Callback<bool(content::RenderProcessHost*)>;
+
+  // The |predicate| is used to determine whether to set preferences for a
+  // render process.
+  explicit RenderProcessPreferences(const Predicate& predicate);
+  virtual ~RenderProcessPreferences();
+
+  int AddEntry(const base::DictionaryValue& entry);
+  void RemoveEntry(int id);
+
+ private:
+  // content::NotificationObserver:
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override;
+
+  void UpdateCache();
+
+  // Manages our notification registrations.
+  content::NotificationRegistrar registrar_;
+
+  Predicate predicate_;
+
+  int next_id_;
+  std::unordered_map<int, std::unique_ptr<base::DictionaryValue>> entries_;
+
+  // We need to convert the |entries_| to ListValue for multiple times, this
+  // caches is only updated when we are sending messages.
+  bool cache_needs_update_;
+  base::ListValue cached_entries_;
+
+  DISALLOW_COPY_AND_ASSIGN(RenderProcessPreferences);
+};
+
+}  // namespace atom
+
+#endif  // ATOM_BROWSER_RENDER_PROCESS_PREFERENCES_H_