Work on GN build of Chrome.

Fixes the rest of the non-rtc and non-vpx linker errors for the chrome target.

BUG=
R=ajwong@chromium.org

Review URL: https://codereview.chromium.org/505853003

Cr-Original-Commit-Position: refs/heads/master@{#291952}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 64275214e0ab409050f048cb7e4b4cf30e3df082

config/features.gni

@@ -164,3 +164,8 @@ enable_chromevox_next = false
 
 # Use brlapi from brltty for braille display support.
 use_brlapi = is_chromeos
+
+# Option controlling the use of GConf (the classic GNOME configuration
+# system).
+# TODO(GYP) also require !embedded to enable.
+use_gconf = is_linux && !is_chromeos

config/linux/BUILD.gn

@@ -39,6 +39,10 @@ pkg_config("gtk") {
   packages = [ "gmodule-2.0", "gtk+-2.0", "gthread-2.0" ]
 }
 
+pkg_config("gtkprint") {
+  packages = [ "gtk+-unix-print-2.0" ]
+}
+
 pkg_config("pangocairo") {
   packages = [ "pangocairo" ]
 }