Bug 1197650 - remove duplicate validity check for newly created fonts. r=m_kato

gfx/thebes/gfxTextRun.cpp

@@ -2652,9 +2652,6 @@ gfxFontGroup::FindNonItalicFaceForChar(gfxFontFamily* aFamily, uint32_t aCh)
     }
 
     nsRefPtr<gfxFont> font = fe->FindOrMakeFont(&mStyle, needsBold);
-    if (!font->Valid()) {
-        return nullptr;
-    }
     return font.forget();
 }