Split //ios/chrome/browser in multiple targets.

ios/chrome/browser/updatable_config/BUILD.gn

Index: ios/chrome/browser/updatable_config/BUILD.gn
diff --git a/ios/chrome/browser/updatable_config/BUILD.gn b/ios/chrome/browser/updatable_config/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..bc9d48e4b59b8333e63d7888a075581ccd330c18
--- /dev/null
+++ b/ios/chrome/browser/updatable_config/BUILD.gn
@@ -0,0 +1,21 @@
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+source_set("updatable_config") {
+  sources = [
+    "updatable_array.h",
+    "updatable_array.mm",
+    "updatable_config_base.h",
+    "updatable_config_base.mm",
+    "updatable_dictionary.h",
+    "updatable_dictionary.mm",
+  ]
+  deps = [
+    "//base",
+    "//ios/public/provider/chrome/browser",
+    "//ios/web",
+    "//net",
+    "//url",
+  ]
+}