fixed pow problem

gfx/src/windows/nsDeviceContextWin.cpp

@@ -222,8 +222,8 @@ PRUint8 * nsDeviceContextWin :: GetGammaTable(void)
 
 void nsDeviceContextWin :: SetGammaTable(PRUint8 * aTable, float aCurrentGamma, float aNewGamma)
 {
-  float fgval = (1.0f / aCurrentGamma) * (1.0f / aNewGamma);
+  double fgval = (1.0f / aCurrentGamma) * (1.0f / aNewGamma);
 
   for (PRInt32 cnt = 0; cnt < 256; cnt++)
-    aTable[cnt] = (PRUint8)(::pow(cnt * (1. / 256.), fgval) * 255.99999999);
+    aTable[cnt] = (PRUint8)(pow((double)cnt * (1. / 256.), fgval) * 255.99999999);
 }