content: Cleanup class/struct forward declarations

content/renderer/media/webrtc/peer_connection_dependency_factory.h

Index: content/renderer/media/webrtc/peer_connection_dependency_factory.h
diff --git a/content/renderer/media/webrtc/peer_connection_dependency_factory.h b/content/renderer/media/webrtc/peer_connection_dependency_factory.h
index 4f52425d31884f1a2e36bd01a95e0e98cd4faafc..2413320cbe59a5e37d6fde1231ef7287011c5948 100644
--- a/content/renderer/media/webrtc/peer_connection_dependency_factory.h
+++ b/content/renderer/media/webrtc/peer_connection_dependency_factory.h
@@ -35,10 +35,7 @@ class Thread;
 
 namespace blink {
 class WebFrame;
-class WebMediaConstraints;
 class WebMediaStream;
-class WebMediaStreamSource;
-class WebMediaStreamTrack;
 class WebRTCPeerConnectionHandler;
 class WebRTCPeerConnectionHandlerClient;
 }
@@ -48,9 +45,6 @@ namespace content {
 class IpcNetworkManager;
 class IpcPacketSocketFactory;
 class WebRtcAudioDeviceImpl;
-class WebRtcLoggingHandlerImpl;
-class WebRtcLoggingMessageFilter;
-struct StreamDeviceInfo;
 
 // Object factory for RTC PeerConnections.
 class CONTENT_EXPORT PeerConnectionDependencyFactory