Expose a method in VariationsService to trigger a seed fetch.

chrome/browser/metrics/variations/variations_request_scheduler.h

Index: chrome/browser/metrics/variations/variations_request_scheduler.h
diff --git a/chrome/browser/metrics/variations/variations_request_scheduler.h b/chrome/browser/metrics/variations/variations_request_scheduler.h
index beb3bbf6de55f6cd4a5865f754de2c5f7d0ef5da..7dd1a2c065b96225e19ad51aeddac9dcdd9ebfed 100644
--- a/chrome/browser/metrics/variations/variations_request_scheduler.h
+++ b/chrome/browser/metrics/variations/variations_request_scheduler.h
@@ -19,7 +19,7 @@ class VariationsRequestScheduler {
  public:
   virtual ~VariationsRequestScheduler();
 
-  // Starts the task on a schedule.
+  // Starts the task. This can be a repeated event or a one-off.
   virtual void Start();
 
   // Resets the scheduler if it is currently on a timer.
@@ -29,6 +29,10 @@ class VariationsRequestScheduler {
   // may have failed.
   void ScheduleFetchShortly();
 
+  // Called when the application has been foregrounded. This may fetch a new
+  // seed.
+  virtual void OnAppEnterForeground();
+
   // Factory method for this class.
   static VariationsRequestScheduler* Create(const base::Closure& task,
                                             PrefService* local_state);