media/win: Make TypeEnumerator FINAL.

Fixes this warning:

In file included from ..\..\media/video/capture/win/pin_base_win.h:15:
..\..\base/memory/ref_counted.h(131,7) :  warning(clang): delete called on 'const media::TypeEnumerator' that has virtual functions but non-virtual destructor [-Wdelete-non-virtual-dtor]
      delete static_cast<const T*>(this);
      ^
..\..\media\video\capture\win\pin_base_win.cc(40,39) :  note(clang): in instantiation of member function 'base::RefCounted<media::TypeEnumerator>::Release' requested here
    base::RefCounted<TypeEnumerator>::Release();
                                      ^
1 warning generated.

BUG=82385
NOTRY=true

Review URL: https://codereview.chromium.org/410833002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284982 0039d316-1c4b-4281-b951-d872f2087c98

media/video/capture/win/pin_base_win.cc

@@ -9,7 +9,7 @@
 namespace media {
 
 // Implement IEnumPins.
-class TypeEnumerator
+class TypeEnumerator FINAL
     : public IEnumMediaTypes,
       public base::RefCounted<TypeEnumerator> {
  public: