Standardize usage of virtual/override/final in chrome/browser/

chrome/browser/feedback/system_logs/log_sources/memory_details_log_source.cc

Index: chrome/browser/feedback/system_logs/log_sources/memory_details_log_source.cc
diff --git a/chrome/browser/feedback/system_logs/log_sources/memory_details_log_source.cc b/chrome/browser/feedback/system_logs/log_sources/memory_details_log_source.cc
index d09b6527b7a1f2826d939c34a601c54f03ccf7d5..1d2e34c85e41f942ac9c00df84cea85477a3a02a 100644
--- a/chrome/browser/feedback/system_logs/log_sources/memory_details_log_source.cc
+++ b/chrome/browser/feedback/system_logs/log_sources/memory_details_log_source.cc
@@ -17,7 +17,7 @@ class SystemLogsMemoryHandler : public MemoryDetails {
 
   // Sends the data to the callback.
   // MemoryDetails override.
-  virtual void OnDetailsAvailable() override {
+  void OnDetailsAvailable() override {
     DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 
     scoped_ptr<SystemLogsResponse> response(new SystemLogsResponse);
@@ -26,7 +26,7 @@ class SystemLogsMemoryHandler : public MemoryDetails {
   }
 
  private:
-  virtual ~SystemLogsMemoryHandler() {}
+  ~SystemLogsMemoryHandler() override {}
   SysLogsSourceCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemLogsMemoryHandler);