Standardize usage of virtual/override/final specifiers.

extensions/browser/process_manager_unittest.cc

Index: extensions/browser/process_manager_unittest.cc
diff --git a/extensions/browser/process_manager_unittest.cc b/extensions/browser/process_manager_unittest.cc
index eff5a15153634c9b7ba3744464a06ded75859687..e30c8c119916e7a7daa6f12a9b7b14010156698e 100644
--- a/extensions/browser/process_manager_unittest.cc
+++ b/extensions/browser/process_manager_unittest.cc
@@ -69,7 +69,7 @@ class ProcessManagerTest : public ExtensionsTest {
         &process_manager_delegate_);
   }
 
-  virtual ~ProcessManagerTest() {}
+  ~ProcessManagerTest() override {}
 
   // Use original_context() to make it clear it is a non-incognito context.
   BrowserContext* original_context() { return browser_context(); }