Remove obsolete path of getSources.

Source/platform/mediastream/MediaStreamCenter.h

Index: Source/platform/mediastream/MediaStreamCenter.h
diff --git a/Source/platform/mediastream/MediaStreamCenter.h b/Source/platform/mediastream/MediaStreamCenter.h
index a41d79c4928b98ccbac6a7083e7586119425355b..b272cc2269adb356a5c90776482a7e7e654f8657 100644
--- a/Source/platform/mediastream/MediaStreamCenter.h
+++ b/Source/platform/mediastream/MediaStreamCenter.h
@@ -50,7 +50,6 @@ namespace blink {
 class AudioSourceProvider;
 class MediaStreamComponent;
 class MediaStreamDescriptor;
-class MediaStreamTrackSourcesRequest;
 
 class PLATFORM_EXPORT MediaStreamCenter final : public blink::WebMediaStreamCenterClient {
     WTF_MAKE_NONCOPYABLE(MediaStreamCenter);
@@ -59,8 +58,6 @@ public:
 
     static MediaStreamCenter& instance();
 
-    bool getMediaStreamTrackSources(MediaStreamTrackSourcesRequest*);
-
     void didCreateMediaStreamTrack(MediaStreamComponent*);
     void didSetMediaStreamTrackEnabled(MediaStreamComponent*);
     bool didStopMediaStreamTrack(MediaStreamComponent*);