[Chromecast] Move some prefs to a different file

Merge-With: eureka-internal/562901

Bug: internal b/178250402
Change-Id: I8c72792306c564c4d22c1f19a715cbb51bcb16fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2798752
Commit-Queue: Kenneth MacKay <[email protected]>
Reviewed-by: Luke Halliwell (slow) <[email protected]>
Cr-Commit-Position: refs/heads/master@{#874794}
diff --git a/chromecast/browser/pref_service_helper.h b/chromecast/browser/pref_service_helper.h
index bd7dc5a..2718899 100644
--- a/chromecast/browser/pref_service_helper.h
+++ b/chromecast/browser/pref_service_helper.h
@@ -8,6 +8,7 @@
 #define CHROMECAST_BROWSER_PREF_SERVICE_HELPER_H_
 
 #include <memory>
+#include <set>
 #include <string>
 
 #include "base/files/file_path.h"
@@ -28,6 +29,10 @@
   static std::unique_ptr<PrefService> CreatePrefService(
       PrefRegistrySimple* registry);
 
+  // Provides names of prefs that take a large amount of storage, and are
+  // therefore stored in a different file.
+  static std::set<std::string> LargePrefNames() __attribute__((weak));
+
  private:
   // Registers any needed preferences for the current platform.
   static void RegisterPlatformPrefs(PrefRegistrySimple* registry);