Flush UKM metrics when backgrounded on Android and iOS.

ios/chrome/browser/application_context.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 IOS_CHROME_BROWSER_APPLICATION_CONTEXT_H_
 #define IOS_CHROME_BROWSER_APPLICATION_CONTEXT_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 31 matching lines @@
 }
 
 namespace physical_web {
 class PhysicalWebDataSource;
 }
 
 namespace rappor {
 class RapporServiceImpl;
 }
 
+namespace ukm {
+class UkmService;
+}
+
 namespace variations {
 class VariationsService;
 }
 
 class ApplicationContext;
 class CRLSetFetcher;
 class IOSChromeIOThread;
 class PrefService;
 
 // Gets the global application context. Cannot return null.
@@ skipping 30 matching lines @@
   virtual ios::ChromeBrowserStateManager* GetChromeBrowserStateManager() = 0;
 
   // Gets the manager for the various metrics-related service, constructing it
   // if necessary.
   virtual metrics_services_manager::MetricsServicesManager*
   GetMetricsServicesManager() = 0;
 
   // Gets the MetricsService used by this application.
   virtual metrics::MetricsService* GetMetricsService() = 0;
 
+  // Gets the UkmService used by this application.
+  virtual ukm::UkmService* GetUkmService() = 0;
+
   // Gets the VariationsService used by this application.
   virtual variations::VariationsService* GetVariationsService() = 0;
 
   // Gets the RapporServiceImpl. May return null.
   virtual rappor::RapporServiceImpl* GetRapporServiceImpl() = 0;
 
   // Gets the ChromeNetLog.
   virtual net_log::ChromeNetLog* GetNetLog() = 0;
 
   // Gets the NetworkTimeTracker.
@@ skipping 17 matching lines @@
 
  protected:
   // Sets the global ApplicationContext instance.
   static void SetApplicationContext(ApplicationContext* context);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ApplicationContext);
 };
 
 #endif  // IOS_CHROME_BROWSER_APPLICATION_CONTEXT_H_