Add virtual and OVERRIDE to base/ implementation files

base/bind_unittest.cc

Index: base/bind_unittest.cc
diff --git a/base/bind_unittest.cc b/base/bind_unittest.cc
index 354b225aa4b441f10a66d2de0f9382361ab49a79..345b71deff509f8d291bc92f841009a5f14cffcf 100644
--- a/base/bind_unittest.cc
+++ b/base/bind_unittest.cc
@@ -66,7 +66,7 @@ class Parent {
 
 class Child : public Parent {
  public:
-  virtual void VirtualSet() { value = kChildValue; }
+  virtual void VirtualSet() OVERRIDE { value = kChildValue; }
   void NonVirtualSet() { value = kChildValue; }
 };
 
@@ -78,7 +78,7 @@ class NoRefParent {
 };
 
 class NoRefChild : public NoRefParent {
-  virtual void VirtualSet() { value = kChildValue; }
+  virtual void VirtualSet() OVERRIDE { value = kChildValue; }
   void NonVirtualSet() { value = kChildValue; }
 };