Expose a method in VariationsService to trigger a seed fetch.

chrome/browser/metrics/variations/variations_service.h

 // Copyright (c) 2012 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_METRICS_VARIATIONS_VARIATIONS_SERVICE_H_
 #define CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_SERVICE_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 35 matching lines @@
   // Calls FetchVariationsSeed once and repeats this periodically. See
   // implementation for details on the period. Must be called after
   // |CreateTrialsFromSeed|.
   void StartRepeatedVariationsSeedFetch();
 
   // Returns the variations server URL, which can vary if a command-line flag is
   // set and/or the variations restrict pref is set in |local_prefs|. Declared
   // static for test purposes.
   static GURL GetVariationsServerURL(PrefService* local_prefs);
 
+  // Called when the application enters foreground. This may trigger a
+  // FetchVariationsSeed call.
+  // TODO(rkaplow): Handle this and the similar event in metrics_service by
+  // observing an 'OnAppEnterForeground' event instead of requiring the frontend
+  // code to notify each service individually.
+  void OnAppEnterForeground();
+
 #if defined(OS_WIN)
   // Starts syncing Google Update Variation IDs with the registry.
   void StartGoogleUpdateRegistrySync();
 #endif
 
   // Exposed for testing.
   void SetCreateTrialsFromSeedCalledForTesting(bool called);
 
   // Exposed for testing.
   static std::string GetDefaultVariationsServerURLForTesting();
@@ skipping 77 matching lines @@
   // Helper that handles synchronizing Variations with the Registry.
   VariationsRegistrySyncer registry_syncer_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(VariationsService);
 };
 
 }  // namespace chrome_variations
 
 #endif  // CHROME_BROWSER_METRICS_VARIATIONS_VARIATIONS_SERVICE_H_