Remove duplicated provideMediaKeysTo() in MediaKeysClient.h

Though MediaKeysController has already provideMediaKeysTo() which is being used by WebViewImpl, MediaKeysClient.h also has provideMediaKeysTo() unnecessary.

BUG=none

Review URL: https://codereview.chromium.org/338713002

git-svn-id: svn://svn.chromium.org/blink/trunk@177184 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/modules/encryptedmedia/MediaKeysClient.h

@@ -25,8 +25,6 @@ protected:
     virtual ~MediaKeysClient() { }
 };
 
-void provideMediaKeysTo(Page&, MediaKeysClient*);
-
 } // namespace WebCore
 
 #endif // MediaKeysClient_h