update string apis

gfx/src/ps/nsAFMObject.cpp

@@ -205,10 +205,10 @@ nsAFMObject::CheckBasicFonts(const nsFont &aFont,PRBool aPrimaryOnly)
 {
 PRInt16     ourfont = -1;
 PRInt32     i,curIndex,score;
-nsString    psfontname;
+nsAutoString    psfontname;
 
   // have to find the correct fontfamily, weight and style
-  psfontname.SetString(aFont.name);
+  psfontname = aFont.name;
   
   // look in the font table for one of the fonts in the passed in list
   for(i=0,curIndex=-1;i<NUM_AFM_FONTS;i++){

gfx/src/ps/nsRenderingContextPS.cpp

@@ -1320,7 +1320,7 @@ nsAutoString    fontFamily;
   mStates->mFontMetrics = mFontMetrics;
 
   // get the fontfamily we are using, not what we want, but what we are using
-  fontFamily.SetString(((nsFontMetricsPS*)mFontMetrics)->mAFMInfo->mPSFontInfo->mFamilyName);
+  fontFamily.AssignWithConversion(((nsFontMetricsPS*)mFontMetrics)->mAFMInfo->mPSFontInfo->mFamilyName);
   fontIndex = ((nsFontMetricsPS*)mFontMetrics)->GetFontIndex();
 
   mPSObj->setscriptfont(fontIndex,fontFamily,fontHeight,font->style,font->variant,font->weight,font->decorations);