[Autofill/Autocomplete Feature] Substring matching instead of prefix matching.

components/autofill/core/common/BUILD.gn

 # Copyright 2014 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("common") {
   sources = [
     "autofill_constants.cc",
     "autofill_constants.h",
     "autofill_data_validation.cc",
     "autofill_data_validation.h",
     "autofill_pref_names.cc",
     "autofill_pref_names.h",
     "autofill_switches.cc",
     "autofill_switches.h",
+    "autofill_util.cc",
+    "autofill_util.h",
     "form_data.cc",
     "form_data.h",
     "form_data_predictions.cc",
     "form_data_predictions.h",
     "form_field_data.cc",
     "form_field_data.h",
     "form_field_data_predictions.cc",
     "form_field_data_predictions.h",
     "password_form.cc",
     "password_form.h",
@@ skipping 16 matching lines @@
   ]
 
   if (is_android) {
     # deps += [ 'autofill_jni_headers' ]  TODO(GYP)
   }
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
+    "autofill_util.unittest.cc",
     "form_data_unittest.cc",
     "form_field_data_unittest.cc",
     "password_form_fill_data_unittest.cc",
     "save_password_progress_logger_unittest.cc",
   ]
 
   deps = [
     ":common",
     "//base",
     "//base:i18n",
     "//testing/gmock",
     "//testing/gtest",
     "//url",
   ]
 }