Update {virtual,override} to follow C++11 style in ppapi.

ppapi/shared_impl/resource_var.h

Index: ppapi/shared_impl/resource_var.h
diff --git a/ppapi/shared_impl/resource_var.h b/ppapi/shared_impl/resource_var.h
index 121859ae0768f64088a113c9e84d2c4cb4534c49..0696d57e13f3652de9203f99ab52dc956dd5e447 100644
--- a/ppapi/shared_impl/resource_var.h
+++ b/ppapi/shared_impl/resource_var.h
@@ -41,8 +41,8 @@ class PPAPI_SHARED_EXPORT ResourceVar : public Var {
   virtual bool IsPending() const = 0;
 
   // Var override.
-  virtual ResourceVar* AsResourceVar() override;
-  virtual PP_VarType GetType() const override;
+  ResourceVar* AsResourceVar() override;
+  PP_VarType GetType() const override;
 
   // Helper function that converts a PP_Var to a ResourceVar. This will
   // return NULL if the PP_Var is not of Resource type.
@@ -51,7 +51,7 @@ class PPAPI_SHARED_EXPORT ResourceVar : public Var {
  protected:
   ResourceVar();
 
-  virtual ~ResourceVar();
+  ~ResourceVar() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ResourceVar);