Create LoadingDataCollector class and have observers rely on it instead of ResourcePrefetchPredictor

chrome/test/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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
@@ skipping 3166 matching lines @@
     "../browser/policy/cloud/cloud_policy_test_utils.cc",
     "../browser/policy/cloud/cloud_policy_test_utils.h",
     "../browser/policy/cloud/remote_commands_invalidator_unittest.cc",
     "../browser/policy/cloud/user_policy_signin_service_unittest.cc",
     "../browser/policy/file_selection_dialogs_policy_handler_unittest.cc",
     "../browser/policy/javascript_policy_handler_unittest.cc",
     "../browser/policy/managed_bookmarks_policy_handler_unittest.cc",
     "../browser/policy/profile_policy_connector_unittest.cc",
     "../browser/predictors/autocomplete_action_predictor_table_unittest.cc",
     "../browser/predictors/autocomplete_action_predictor_unittest.cc",
+    "../browser/predictors/loading_data_collector_unittest.cc",
     "../browser/predictors/loading_predictor_unittest.cc",
     "../browser/predictors/resource_prefetch_common_unittest.cc",
     "../browser/predictors/resource_prefetch_predictor_tables_unittest.cc",
     "../browser/predictors/resource_prefetch_predictor_test_util.cc",
     "../browser/predictors/resource_prefetch_predictor_test_util.h",
     "../browser/predictors/resource_prefetch_predictor_unittest.cc",
     "../browser/predictors/resource_prefetcher_unittest.cc",
     "../browser/prefs/chrome_command_line_pref_store_proxy_unittest.cc",
     "../browser/prefs/chrome_command_line_pref_store_ssl_manager_unittest.cc",
     "../browser/prefs/chrome_command_line_pref_store_unittest.cc",
@@ skipping 1944 matching lines @@
 }
 
 if (is_win) {
   loadable_module("conflicts_dll") {
     testonly = true
     sources = [
       "conflicts/conflicts_dll.cc",
     ]
   }
 }