predictors: Basic browsertest checks predictor learning.

chrome/browser/predictors/resource_prefetch_predictor.h

Index: chrome/browser/predictors/resource_prefetch_predictor.h
diff --git a/chrome/browser/predictors/resource_prefetch_predictor.h b/chrome/browser/predictors/resource_prefetch_predictor.h
index 1de5b6bc52d231d732df53781ed306b621dfae00..3ab2ccbab7d794226e94de1b6ca24d15454a79b6 100644
--- a/chrome/browser/predictors/resource_prefetch_predictor.h
+++ b/chrome/browser/predictors/resource_prefetch_predictor.h
@@ -163,6 +163,7 @@ class ResourcePrefetchPredictor
  private:
   friend class ::PredictorsHandler;
   friend class ResourcePrefetchPredictorTest;
+  friend class ResourcePrefetchPredictorBrowserTest;

[pasko, 2016/11/02 19:37:01]

not necessary for this change, please add when it is necessary, at which point
we will discuss how too many friends can be avoided

[alexilin, 2016/11/03 13:49:08]

Thanks for the pointing, we don't need it anymore since we check all resources
in the observer. (I used private caches for checking earlier).
Remove it for now, we'll try to avoid to add this friendship in further CLs.

 
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, DeleteUrls);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest,