Create a skeleton OfflineMetricsCollector to accumulate 'offline' and 'online' days
as described in go/offline-prefetch-metrics.

This is a placeholder for main classes/hookup, the actual implementation of the
OfflineMetricsCollector comes as subsequent CL.


Bug: 701939
Change-Id: Ic8e7f8c3f0f4e07f8bd363ace57f11915ea61f5f
Reviewed-on: https://chromium-review.googlesource.com/517689
Commit-Queue: Dmitry Titov <[email protected]>
Reviewed-by: Filip Gorski <[email protected]>
Reviewed-by: Justin DeWitt <[email protected]>
Cr-Commit-Position: refs/heads/master@{#476065}
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 1f71e2b..2159a8a 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -2184,6 +2184,8 @@
       "android/offline_pages/request_coordinator_factory.h",
       "offline_pages/background_loader_offliner.cc",
       "offline_pages/background_loader_offliner.h",
+      "offline_pages/prefetch/offline_metrics_collector_impl.cc",
+      "offline_pages/prefetch/offline_metrics_collector_impl.h",
       "offline_pages/prefetch/prefetch_service_factory.cc",
       "offline_pages/prefetch/prefetch_service_factory.h",
     ]