One more OVERRIDE test that the code should already pass.

tools/clang/plugins/tests/overridden_methods.h

 // Copyright (c) 2011 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.
 
 #ifndef OVERRIDDEN_METHODS_H_
 #define OVERRIDDEN_METHODS_H_
 
 // Should warn about overriding of methods.
 class BaseClass {
  public:
   virtual ~BaseClass() {}
   virtual void SomeMethod() = 0;
   virtual void SomeOtherMethod() = 0;
   virtual void SomeInlineMethod() = 0;
+  virtual void SomeNonPureBaseMethod() {}
 };
 
 class InterimClass : public BaseClass {
   // Should not warn about pure virtual methods.
   virtual void SomeMethod() = 0;
 };
 
 namespace WebKit {
 class WebKitObserver {
  public:
@@ skipping 14 matching lines @@
   // Should not warn about destructors.
   virtual ~DerivedClass() {}
   // Should warn.
   virtual void SomeMethod();
   // Should not warn if marked as override.
   virtual void SomeOtherMethod() override;
   // Should warn for inline implementations.
   virtual void SomeInlineMethod() {}
   // Should not warn if overriding a method whose origin is WebKit.
   virtual void WebKitModifiedSomething();
+  // Should warn if overridden method isn't pure.
+  virtual void SomeNonPureBaseMethod() {}
 };
 
 #endif  // OVERRIDDEN_METHODS_H_