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

chrome/browser/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/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 954 matching lines @@
     "policy/schema_registry_service_factory.h",
     "predictors/autocomplete_action_predictor.cc",
     "predictors/autocomplete_action_predictor.h",
     "predictors/autocomplete_action_predictor_factory.cc",
     "predictors/autocomplete_action_predictor_factory.h",
     "predictors/autocomplete_action_predictor_table.cc",
     "predictors/autocomplete_action_predictor_table.h",
     "predictors/glowplug_key_value_data.h",
     "predictors/glowplug_key_value_table.cc",
     "predictors/glowplug_key_value_table.h",
+    "predictors/loading_data_collector.cc",
+    "predictors/loading_data_collector.h",
     "predictors/loading_predictor.cc",
     "predictors/loading_predictor.h",
     "predictors/loading_predictor_android.cc",
     "predictors/loading_predictor_android.h",
     "predictors/loading_predictor_config.cc",
     "predictors/loading_predictor_config.h",
     "predictors/loading_predictor_factory.cc",
     "predictors/loading_predictor_factory.h",
     "predictors/predictor_database.cc",
     "predictors/predictor_database.h",
@@ skipping 3800 matching lines @@
       "media/pepper_cdm_test_constants.cc",
       "media/pepper_cdm_test_constants.h",
     ]
   }
 }
 
 service_manifest("preferences_forwarder_manifest") {
   name = "preferences_forwarder"
   source = "prefs/forwarder_manifest.json"
 }