Add virtual and OVERRIDE to base/ implementation files

base/memory/weak_ptr_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "base/message_loop.h"
 #include "base/synchronization/waitable_event.h"
@@ skipping 26 matching lines @@
 struct Base { std::string member; };
 struct Derived : Base {};
 
 struct Producer : SupportsWeakPtr<Producer> {};
 struct Consumer { WeakPtr<Producer> producer; };
 
 // Helper class to create and destroy weak pointer copies
 // and delete objects on a background thread.
 class BackgroundThread : public Thread {
  public:
-  BackgroundThread()
-      : Thread("owner_thread") {
-  }
+  BackgroundThread() : Thread("owner_thread") {}
 
-  ~BackgroundThread() {
+  virtual ~BackgroundThread() {
     Stop();
   }
 
   void CreateConsumerFromProducer(Consumer** consumer, Producer* producer) {
     WaitableEvent completion(true, false);
     message_loop()->PostTask(
         FROM_HERE,
         base::Bind(&BackgroundThread::DoCreateFromProducer, consumer, producer,
                    &completion));
     completion.Wait();
@@ skipping 277 matching lines @@
   Base data;
   data.member = "123456";
   WeakPtrFactory<Base> factory(&data);
   WeakPtr<Base> ptr = factory.GetWeakPtr();
   EXPECT_EQ(&data, ptr.get());
   EXPECT_EQ(data.member, (*ptr).member);
   EXPECT_EQ(data.member, ptr->member);
 }
 
 }  // namespace base