predictors: Add origin learning.

chrome/browser/predictors/resource_prefetch_common.h

Index: chrome/browser/predictors/resource_prefetch_common.h
diff --git a/chrome/browser/predictors/resource_prefetch_common.h b/chrome/browser/predictors/resource_prefetch_common.h
index bee3ae2b145a2318709908c59bb8e7bc11237ce1..627dab0754205a7065ce8b62c525c91482ae6d7f 100644
--- a/chrome/browser/predictors/resource_prefetch_common.h
+++ b/chrome/browser/predictors/resource_prefetch_common.h
@@ -111,6 +111,8 @@ struct ResourcePrefetchPredictorConfig {
 
   // The maximum number of resources to store per entry.
   size_t max_resources_per_entry;
+  // The maximum number of origins to store per entry.
+  size_t max_origins_per_entry;
   // The number of consecutive misses after we stop tracking a resource URL.
   size_t max_consecutive_misses;
 
@@ -129,6 +131,8 @@ struct ResourcePrefetchPredictorConfig {
   bool is_url_learning_enabled;
   // True iff the predictor could use manifests.
   bool is_manifests_enabled;
+  // True iff the origin-based prediction is enabled.
+  bool is_origin_prediction_enabled;
 };
 
 }  // namespace predictors