Update the Website Settings page when the power consumption is updated.

components/power/origin_power_map.h

 // Copyright 2014 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 COMPONENTS_POWER_ORIGIN_POWER_MAP_H_
 #define COMPONENTS_POWER_ORIGIN_POWER_MAP_H_
 
 #include <map>
 
+#include "base/observer_list.h"
 #include "components/keyed_service/core/keyed_service.h"
+#include "components/power/origin_power_map_observer.h"
 #include "url/gurl.h"
 
 namespace power {
 
 // Tracks app and website origins and how much power they are consuming while
 // running.
 class OriginPowerMap : public KeyedService {
  public:
   typedef std::map<GURL, int> PercentOriginMap;
 
   OriginPowerMap();
   virtual ~OriginPowerMap();
 
   // Returns the integer percentage usage of the total power consumed by a
   // given URL's origin.
   int GetPowerForOrigin(const GURL& url);
 
   // Adds a certain amount of power consumption to a given URL's origin.
   // |power| is a platform-specific heuristic estimating power consumption.
   void AddPowerForOrigin(const GURL& url, double power);
 
   // Returns a map of all origins to the integer percentage usage of power
   // consumed.
   PercentOriginMap GetPercentOriginMap();
 
+  // Adds/removes observer.
+  void AddObserver(OriginPowerMapObserver* observer);
+  void RemoveObserver(OriginPowerMapObserver* observer);
+
+  // Notifies observers to let them know that the origin power map has finished
+  // updating.
+  void OnPowerConsumptionUpdated();

[Daniel Erat, 2014/08/29 21:14:02]

mind giving this a different name from the OriginPowerMapObserver method to make
it less likely that people will get confused? maybe something like
"OnUpdatesDone" or "OnAllOriginsUpdated"? this also hopefully makes it clearer
that the entire round of updates is done, rather than e.g. this being called
after each AddPowerForOrigin call.

[Daniel Nishi, 2014/09/02 16:30:30]

Done.

+
  private:
   // OriginMap maps a URL to the amount of power consumed by the URL using the
   // same units as |total_consumed_|.
   typedef std::map<GURL, double> OriginMap;
   OriginMap origin_map_;
 
   // Total amount of power consumed using units determined by
   // the power heuristics available to the platform.
   double total_consumed_;
 
+  ObserverList<OriginPowerMapObserver> observers_;
+
   DISALLOW_COPY_AND_ASSIGN(OriginPowerMap);
 };
 
 }  // namespace power
 
 #endif  // COMPONENTS_POWER_ORIGIN_POWER_MAP_H_