Enable strict-virtual-specifiers for iOS builds.

chrome/browser/metrics/variations/variations_request_scheduler_mobile.h

Index: chrome/browser/metrics/variations/variations_request_scheduler_mobile.h
diff --git a/chrome/browser/metrics/variations/variations_request_scheduler_mobile.h b/chrome/browser/metrics/variations/variations_request_scheduler_mobile.h
index 651e984f3b610351204834af4a450359b2e060b7..2ad9d782dcb41679cc9c43b0653a70e5cbda05da 100644
--- a/chrome/browser/metrics/variations/variations_request_scheduler_mobile.h
+++ b/chrome/browser/metrics/variations/variations_request_scheduler_mobile.h
@@ -20,12 +20,12 @@ class VariationsRequestSchedulerMobile : public VariationsRequestScheduler {
   // is the PrefService that contains the time of the last fetch.
   explicit VariationsRequestSchedulerMobile(const base::Closure& task,
                                             PrefService* local_state);
-  virtual ~VariationsRequestSchedulerMobile();
+  ~VariationsRequestSchedulerMobile() override;
 
   // Base class overrides.
-  virtual void Start() override;
-  virtual void Reset() override;
-  virtual void OnAppEnterForeground() override;
+  void Start() override;
+  void Reset() override;
+  void OnAppEnterForeground() override;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(VariationsRequestSchedulerMobileTest,