Stop assuming anything about result of MFStartup()

media/base/win/mf_initializer.h

Index: media/base/win/mf_initializer.h
diff --git a/media/base/win/mf_initializer.h b/media/base/win/mf_initializer.h
index 6a1b6cafd230af7ec208cbf9e2a8bd2a52101898..982cdc6c01b34b17cf1144bd1527e4430aa24d4b 100644
--- a/media/base/win/mf_initializer.h
+++ b/media/base/win/mf_initializer.h
@@ -9,8 +9,11 @@
 
 namespace media {
 
-// Makes sure MFStartup() is called exactly once.
-MF_INITIALIZER_EXPORT void InitializeMediaFoundation();
+// Makes sure MFStartup() is called exactly once.  Returns true if Media
+// Foundation is available and has been initialized successfully.  Note that it
+// is expected to return false on an "N" edition of Windows, see
+// https://en.wikipedia.org/wiki/Windows_7_editions#Special-purpose_editions.
+MF_INITIALIZER_EXPORT bool InitializeMediaFoundation();
 
 }  // namespace media