wifi: Remove unnecessary class declarations

src/wifi/model/block-ack-manager.h

@@ -32,7 +32,6 @@ namespace ns3 {
 
 class MgtAddBaResponseHeader;
 class MgtAddBaRequestHeader;
-class MgtDelBaHeader;
 class MacTxMiddle;
 class WifiMacQueue;
 

src/wifi/model/dca-txop.h

@@ -31,11 +31,8 @@ class DcfState;
 class DcfManager;
 class WifiMacQueue;
 class MacLow;
-class WifiMacParameters;
 class MacTxMiddle;
 class RandomStream;
-class MacStation;
-class MacStations;
 
 /**
  * \brief handle packet fragmentation and retransmissions.
@@ -159,8 +156,6 @@ public:
 
 private:
   class TransmissionListener;
-  class NavListener;
-  class PhyListener;
   class Dcf;
   friend class Dcf;
   friend class TransmissionListener;

src/wifi/model/dcf-manager.h

@@ -26,7 +26,6 @@
 namespace ns3 {
 
 class WifiPhy;
-class WifiMac;
 class MacLow;
 class PhyListener;
 class LowDcfListener;

src/wifi/model/mac-low.h

@@ -36,9 +36,6 @@ class AmpduAggregationTest;
 
 namespace ns3 {
 
-class WifiPhy;
-class WifiMac;
-class EdcaTxopN;
 class WifiMacQueue;
 
 /**

src/wifi/model/regular-wifi-mac.h

@@ -27,7 +27,6 @@
 
 namespace ns3 {
 
-class Dcf;
 class MacLow;
 class MacRxMiddle;
 class MacTxMiddle;

src/wifi/model/wifi-channel.h

@@ -25,9 +25,6 @@
 
 namespace ns3 {
 
-class WifiNetDevice;
-class WifiPhy;
-
 /**
  * \brief Wifi Channel interface specification
  * \ingroup wifi