Add chrome.power extension API.

chrome/browser/extensions/api/power/power_api_manager.h

+// Copyright (c) 2013 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_EXTENSIONS_API_POWER_POWER_API_MANAGER_H_
+#define CHROME_BROWSER_EXTENSIONS_API_POWER_POWER_API_MANAGER_H_
+
+#include <map>
+#include <string>
+
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/singleton.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+#include "content/public/browser/power_save_blocker.h"
+
+namespace extensions {
+
+class PowerApiManager : public content::NotificationObserver {
+ public:
+  // Different levels of power-management-overriding.  Keep in ascending
+  // order so that higher-valued levels' behavior subsumes lower-valued
+  // ones' behavior.
+  enum Level {
+    // Prevents the system from sleeping due to user inactivity.
+    LEVEL_SYSTEM = 0,
+
+    // Prevents the system from dimming the display, turning the display
+    // off, or sleeping due to user inactivity.
+    LEVEL_DISPLAY = 1,

[not at google - send to devlin, 2013/03/19 21:16:39]

if it were an enum, you wouldn't need this definition in the first place.

[Daniel Erat, 2013/03/19 23:39:38]

Done.

+  };
+
+  typedef base::Callback<scoped_ptr<content::PowerSaveBlocker>(
+      content::PowerSaveBlocker::PowerSaveBlockerType,
+      const std::string&)> CreateBlockerFunction;
+
+  static PowerApiManager* GetInstance();
+
+  void set_create_blocker_function_for_testing(
+      scoped_ptr<CreateBlockerFunction> function) {
+    create_blocker_function_.swap(function);
+  }
+
+  // Adds an extension lock at |level| for |extension_id|, replacing the
+  // extension's existing lock, if any.
+  void AddRequest(const std::string& extension_id, Level level);
+
+  // Removes an extension lock for an extension. Calling this for an
+  // extension id without a lock will do nothing.
+  void RemoveRequest(const std::string& extension_id);
+
+  // Overridden from content::NotificationObserver.
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+ private:
+  friend struct DefaultSingletonTraits<PowerApiManager>;
+
+  PowerApiManager();
+  virtual ~PowerApiManager();
+
+  // Updates |power_save_blocker_| and |current_level_| after iterating
+  // over |extension_levels_|.
+  void UpdatePowerSaveBlocker();
+
+  content::NotificationRegistrar registrar_;
+
+  // Alternate function that should be called to create PowerSaveBlocker
+  // objects.  Tests can use this to override what would've been done
+  // instead of actually changing the system power-saving settings.  If
+  // NULL, content::PowerSaveBlocker::Create() is used.
+  scoped_ptr<CreateBlockerFunction> create_blocker_function_;
+
+  scoped_ptr<content::PowerSaveBlocker> power_save_blocker_;
+
+  // Current level used by |power_save_blocker_|.  Meaningless if
+  // |power_save_blocker_| is NULL.
+  Level current_level_;
+
+  // Make from extension ID to the corresponding level for each extension
+  // that has an outstanding request.
+  typedef std::map<std::string, Level> ExtensionLevelMap;
+  ExtensionLevelMap extension_levels_;
+
+  DISALLOW_COPY_AND_ASSIGN(PowerApiManager);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_POWER_POWER_API_MANAGER_H_