fixing linux fallout from 328906. patch from Simon Montague <smontagu@smontagu.org>. r=pavlov

gfx/thebes/public/gfxPangoFonts.h

@@ -79,6 +79,11 @@ public:
 
     virtual gfxTextRun *MakeTextRun(const nsAString& aString);
 
+    gfxPangoFont *GetFontAt(PRInt32 i) {
+        return NS_STATIC_CAST(gfxPangoFont*, 
+                              NS_STATIC_CAST(gfxFont*, mFonts[i]));
+    }
+
 protected:
     static PRBool FontCallback (const nsAString& fontName,
                                 const nsAString& genericName,

gfx/thebes/src/gfxPangoFonts.cpp

@@ -623,7 +623,7 @@ gfxPangoTextRun::~gfxPangoTextRun()
 void
 gfxPangoTextRun::EnsurePangoLayout(gfxContext *aContext)
 {
-    gfxPangoFont *pf = ((gfxPangoFont*) mGroup->GetFontList()[0]);
+    nsRefPtr<gfxPangoFont> pf = mGroup->GetFontAt(0);
 
     if (mPangoLayout == nsnull) {
         NS_ConvertUTF16toUTF8 u8str(mString);