Expose a method in VariationsService to trigger a seed fetch.

chrome/browser/metrics/variations/variations_request_scheduler.cc

Index: chrome/browser/metrics/variations/variations_request_scheduler.cc
diff --git a/chrome/browser/metrics/variations/variations_request_scheduler.cc b/chrome/browser/metrics/variations/variations_request_scheduler.cc
index ff437a8c9d450aa7a78fac1127e4e05bc15b1048..8f62c350f3963fcdc7d23dbf3f7a67c40b15fe50 100644
--- a/chrome/browser/metrics/variations/variations_request_scheduler.cc
+++ b/chrome/browser/metrics/variations/variations_request_scheduler.cc
@@ -36,6 +36,10 @@ void VariationsRequestScheduler::ScheduleFetchShortly() {
                         task_);
 }
 
+void VariationsRequestScheduler::OnAppEnterForeground() {
+  NOTREACHED() << "Attempted to OnAppEnterForeground on non-mobile device";
+}
+
 base::Closure VariationsRequestScheduler::task() const {
   return task_;
 }