Fixing compile warnings on Linux

gfx/src/motif/nsDeviceContextUnix.cpp

@@ -280,7 +280,7 @@ void nsDeviceContextUnix :: InstallColormap()
   else // We have StaticGray, StaticColor or TrueColor
     mWriteable = PR_FALSE;
 
-  mNumCells = pow(2, mDepth);
+  mNumCells = (PRUint32) pow(2, mDepth);
 
   mColormap = wa.colormap;
 

gfx/src/motif/nsImageUnix.h

@@ -80,9 +80,9 @@ public:
    */
   PRInt32  CalcBytesSpan(PRUint32  aWidth);
   PRBool  SetAlphaMask(nsIImage *aTheMask);
-  virtual void  SetAlphaLevel(PRInt32 aAlphaLevel) {}
+  virtual void  SetAlphaLevel(PRInt32 /* aAlphaLevel */) {}
   virtual PRInt32 GetAlphaLevel() {return(0);}
-  virtual void  MoveAlphaMask(PRInt32 aX, PRInt32 aY) {}
+  virtual void  MoveAlphaMask(PRInt32 /* aX */, PRInt32 /* aY */) {}
 
 private:
   void CreateImage(nsDrawingSurface aSurface);