predictors: Refactor resource_prefetch_predictor triggering.

Triggering and policy move to LoadingPredictor, instead of being in
ResourcePrefetchPredictor. As a consequence, rename
ResourcePrefetchPredictorObserver.

BUG=715525

Review-Url: https://codereview.chromium.org/2887133003
Cr-Commit-Position: refs/heads/master@{#476313}
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index f5c2bb7..189880ba 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -696,6 +696,8 @@
     "net/file_downloader.h",
     "net/http_server_properties_manager_factory.cc",
     "net/http_server_properties_manager_factory.h",
+    "net/loading_predictor_observer.cc",
+    "net/loading_predictor_observer.h",
     "net/net_error_diagnostics_dialog.h",
     "net/net_error_diagnostics_dialog_mac.cc",
     "net/net_error_diagnostics_dialog_win.cc",
@@ -723,8 +725,6 @@
     "net/referrer.h",
     "net/request_source_bandwidth_histograms.cc",
     "net/request_source_bandwidth_histograms.h",
-    "net/resource_prefetch_predictor_observer.cc",
-    "net/resource_prefetch_predictor_observer.h",
     "net/safe_search_util.cc",
     "net/safe_search_util.h",
     "net/sdch_owner_pref_storage.cc",