Bug 740200 - Enable content pref; r=mattwoodrow

gfx/thebes/gfxPlatformGtk.cpp

@@ -92,7 +92,7 @@ gfxPlatformGtk::gfxPlatformGtk()
     UpdateFontList();
 #endif
     uint32_t canvasMask = (1 << BACKEND_CAIRO) | (1 << BACKEND_SKIA);
-    uint32_t contentMask = 0;
+    uint32_t contentMask = (1 << BACKEND_CAIRO) | (1 << BACKEND_SKIA);
     InitBackendPrefs(canvasMask, contentMask);
 }