firefox: Use more system libraries

Use system libpng with apng support.
Use the system icu which works fine in newer firefox builds.
Use jemalloc to speed up memory allocations and reduce fragmentation.

pkgs/applications/networking/browsers/firefox/default.nix

@@ -3,7 +3,7 @@
 , freetype, fontconfig, file, alsaLib, nspr, nss, libnotify
 , yasm, mesa, sqlite, unzip, makeWrapper, pysqlite
 , hunspell, libevent, libstartup_notification, libvpx
-, cairo, gstreamer, gst_plugins_base, icu
+, cairo, gst_all_1, icu, libpng, jemalloc
 , enableGTK3 ? false
 , debugBuild ? false
 , # If you want the resulting program to call itself "Firefox" instead
@@ -34,7 +34,8 @@ stdenv.mkDerivation rec {
       xlibs.libXScrnSaver xlibs.scrnsaverproto pysqlite
       xlibs.libXext xlibs.xextproto sqlite unzip makeWrapper
       hunspell libevent libstartup_notification libvpx cairo
-      gstreamer gst_plugins_base icu
+      gst_all_1.gstreamer gst_all_1.gst-plugins-base icu libpng
+      jemalloc
     ]
     ++ lib.optional enableGTK3 gtk3;
 
@@ -48,26 +49,27 @@ stdenv.mkDerivation rec {
       "--with-system-nss"
       "--with-system-libevent"
       "--with-system-libvpx"
-      # "--with-system-png" # needs APNG support
-      # "--with-system-icu" # causes ‘ar: invalid option -- 'L'’ in Firefox 28.0
+      "--with-system-png" # needs APNG support
+      "--with-system-icu"
       "--enable-system-ffi"
       "--enable-system-hunspell"
       "--enable-system-pixman"
       "--enable-system-sqlite"
       "--enable-system-cairo"
-      "--enable-gstreamer"
+      "--enable-gstreamer=1.0"
       "--enable-startup-notification"
-      # "--enable-content-sandbox"            # available since 26.0, but not much info available
-      # "--enable-content-sandbox-reporter"   # keeping disabled for now
+      "--enable-content-sandbox"            # available since 26.0, but not much info available
+      "--disable-content-sandbox-reporter"  # keeping disabled for now
       "--disable-crashreporter"
       "--disable-tests"
       "--disable-necko-wifi" # maybe we want to enable this at some point
       "--disable-installer"
       "--disable-updater"
       "--disable-pulseaudio"
+      "--enable-jemalloc"
     ]
     ++ lib.optional enableGTK3 "--enable-default-toolkit=cairo-gtk3"
-    ++ (if debugBuild then [ "--enable-debug" "--enable-profiling"]
+    ++ (if debugBuild then [ "--enable-debug" "--enable-profiling" ]
                       else [ "--disable-debug" "--enable-release"
                              "--enable-optimize${lib.optionalString (stdenv.system == "i686-linux") "=-O1"}"
                              "--enable-strip" ])

pkgs/top-level/all-packages.nix

@@ -11409,6 +11409,7 @@ let
   firefox = callPackage ../applications/networking/browsers/firefox {
     inherit (gnome) libIDL;
     inherit (pythonPackages) pysqlite;
+    libpng = libpng_apng;
     enableGTK3 = false;
   };