Standardize usage of virtual/override/final in content/

content/child/webthread_impl.cc

Index: content/child/webthread_impl.cc
diff --git a/content/child/webthread_impl.cc b/content/child/webthread_impl.cc
index 1f40b08bdcdd94adb3a4256335be77ab98884fe0..ec80b70e86e2c885ce8522121bf2403a9504ac77 100644
--- a/content/child/webthread_impl.cc
+++ b/content/child/webthread_impl.cc
@@ -24,11 +24,11 @@ class WebThreadBase::TaskObserverAdapter
   TaskObserverAdapter(WebThread::TaskObserver* observer)
       : observer_(observer) {}
 
-  virtual void WillProcessTask(const base::PendingTask& pending_task) override {
+  void WillProcessTask(const base::PendingTask& pending_task) override {
     observer_->willProcessTask();
   }
 
-  virtual void DidProcessTask(const base::PendingTask& pending_task) override {
+  void DidProcessTask(const base::PendingTask& pending_task) override {
     observer_->didProcessTask();
   }