Remove USE(GSTREAMER) and USE(WEBAUDIO_GSTREAMER) guards.

Source/core/platform/graphics/MediaPlayer.cpp

Index: Source/core/platform/graphics/MediaPlayer.cpp
diff --git a/Source/core/platform/graphics/MediaPlayer.cpp b/Source/core/platform/graphics/MediaPlayer.cpp
index 4baa33721e588c2603d2551acae6b44e1d73130f..9bb8ce1117929255985c5a885d9a0ab420a4a62a 100644
--- a/Source/core/platform/graphics/MediaPlayer.cpp
+++ b/Source/core/platform/graphics/MediaPlayer.cpp
@@ -47,11 +47,6 @@
 #include "MediaSource.h"
 #endif
 
-#if USE(GSTREAMER)
-#include "MediaPlayerPrivateGStreamer.h"
-#define PlatformMediaEngineClassName MediaPlayerPrivateGStreamer
-#endif
-
 #include "MediaPlayerPrivateChromium.h"
 #define PlatformMediaEngineClassName MediaPlayerPrivate
 
@@ -1012,16 +1007,6 @@ void MediaPlayer::resetMediaEngines()
     installedMediaEngines(ResetEngines);
 }
 
-#if USE(GSTREAMER)
-void MediaPlayer::simulateAudioInterruption()
-{
-    if (!m_private)
-        return;
-
-    m_private->simulateAudioInterruption();
-}
-#endif
-
 }
 
 #endif