Add dconf to instrumented libraries

This is in preparation of the removal of the deprecated gconf.

Bug: 768027
Change-Id: Id81087ceb304c4124b810544c2244fd3123f0ef6
Reviewed-on: https://chromium-review.googlesource.com/775360Reviewed-by: Evgeniy Stepanov <eugenis@chromium.org>
Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Tim Brown <timbrown@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517267}

third_party/instrumented_libraries/BUILD.gn

@@ -110,6 +110,7 @@ if (use_locally_built_instrumented_libraries) {
       ":libdbus-glib-1-2",
       ":libdbusmenu",
       ":libdbusmenu-glib4",
+      ":libdconf1",
       ":libexpat1",
       ":libffi6",
       ":libfontconfig1",
@@ -460,6 +461,13 @@ if (use_locally_built_instrumented_libraries) {
     pre_build = "scripts/pre-build/autogen.sh"
   }
 
+  instrumented_library("libdconf1") {
+    extra_configure_flags = [
+      "--disable-static",
+      "--disable-introspection",
+    ]
+  }
+
   instrumented_library("libexpat1") {
     extra_configure_flags = [ "--disable-static" ]
   }

third_party/instrumented_libraries/scripts/install-build-deps.sh

@@ -28,6 +28,7 @@ libdbus-1-3 \
 libdbus-glib-1-2 \
 libdbusmenu \
 libdbusmenu-glib4 \
+libdconf1 \
 libexpat1 \
 libffi6 \
 libfontconfig1 \