Move some proxy config code out of src/chrome

BUG=658015

Review-Url: https://codereview.chromium.org/2442313003
Cr-Commit-Position: refs/heads/master@{#428257}
diff --git a/chromeos/BUILD.gn b/chromeos/BUILD.gn
index 95dd7f0..6a416a8 100644
--- a/chromeos/BUILD.gn
+++ b/chromeos/BUILD.gn
@@ -33,6 +33,7 @@
     "//components/device_event_log",
     "//components/onc",
     "//components/policy/proto",
+    "//components/pref_registry",
     "//components/prefs",
     "//components/proxy_config",
     "//components/signin/core/account_id",
@@ -41,6 +42,7 @@
     "//crypto:platform",
     "//google_apis",
     "//net",
+    "//skia",  # For components/user_manager
     "//third_party/icu",
     "//third_party/libxml",
     "//third_party/protobuf:protobuf_lite",