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

ios/chrome/browser/web_resource/BUILD.gn

 # 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.
 
-static_library("client_update_protocol") {
+source_set("web_resource") {
   sources = [
-    "ecdsa.cc",
-    "ecdsa.h",
+    "web_resource_util.cc",
+    "web_resource_util.h",
   ]
-
   deps = [
     "//base",
-    "//crypto",
+    "//components/web_resource",
+    "//ios/web",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
-    "ecdsa_unittest.cc",
+    "web_resource_util_unittest.cc",
   ]
-
   deps = [
-    ":client_update_protocol",
+    ":web_resource",
     "//base",
-    "//crypto",
+    "//ios/web",
     "//testing/gtest",
   ]
 }