Make BackgroundBudgetService calls asynchronous.

chrome/browser/budget_service/background_budget_service.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_BUDGET_SERVICE_BACKGROUND_BUDGET_SERVICE_H_
 #define CHROME_BROWSER_BUDGET_SERVICE_BACKGROUND_BUDGET_SERVICE_H_
 
 #include <memory>
 #include <string>
 
+#include "base/callback_forward.h"
 #include "base/gtest_prod_util.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "url/gurl.h"
 
 class Profile;
 
 namespace base {
 class Clock;
 }
 
@@ skipping 13 matching lines @@
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
   enum class CostType {
     // The cost of silencing a push message.
     SILENT_PUSH = 0,
   };
 
   // Query for the base cost for any background processing.
   static double GetCost(CostType type);
 
-  // Get the budget associated with the origin. This is returned as the double
-  // budget. Budget will be a value between 0.0 and
+  using GetBudgetCallback = base::Callback<void(double /* budget */)>;

[johnme, 2016/06/15 09:59:06]

Nit: you don't need to comment out budget.

[harkness, 2016/06/20 11:22:19]

Done.

+
+  // Get the budget associated with the origin. This is passed to the
+  // callback. Budget will be a value between 0.0 and
   // SiteEngagementScore::kMaxPoints.
-  double GetBudget(const GURL& origin);
+  void GetBudget(const GURL& origin, const GetBudgetCallback& callback);
 
   // Store the budget associated with the origin. Budget should be a value
   // between 0.0 and SiteEngagementScore::kMaxPoints.
-  void StoreBudget(const GURL& origin, double budget);
+  void StoreBudget(const GURL& origin,
+                   double budget,
+                   const base::Closure& closure);

[johnme, 2016/06/15 09:59:06]

Nit: please rename this to done_callback and/or comment that it will be run once
the budget has finished being stored.

[harkness, 2016/06/20 11:22:19]

Done.

 
  private:
   friend class BackgroundBudgetServiceTest;
 
   // Used to allow tests to fast forward/reverse time.
   void SetClockForTesting(std::unique_ptr<base::Clock> clock);
 
   // The clock used to vend times.
   std::unique_ptr<base::Clock> clock_;
 
   Profile* profile_;
   DISALLOW_COPY_AND_ASSIGN(BackgroundBudgetService);
 };
 
 #endif  // CHROME_BROWSER_BUDGET_SERVICE_BACKGROUND_BUDGET_SERVICE_H_