predictors: Support for several types of hints in LoadingPredictor.

This CL adds a skeleton for preconnect and preresolve support in 
LoadingPredictor.

Bug: 699080
Change-Id: Ib4d8752fe681827deae9b4986aac7d4ebc18eeb0
Reviewed-on: https://chromium-review.googlesource.com/555991
Commit-Queue: Alexandr Ilin <[email protected]>
Reviewed-by: Benoit L <[email protected]>
Cr-Commit-Position: refs/heads/master@{#484893}
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 4f9d7ce..0385b36 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -990,6 +990,8 @@
     "predictors/loading_predictor_factory.h",
     "predictors/loading_stats_collector.cc",
     "predictors/loading_stats_collector.h",
+    "predictors/preconnect_manager.cc",
+    "predictors/preconnect_manager.h",
     "predictors/predictor_database.cc",
     "predictors/predictor_database.h",
     "predictors/predictor_database_factory.cc",