Precache manifest should not be added to fetcher pool which is full

components/precache/core/precache_fetcher.h

Index: components/precache/core/precache_fetcher.h
diff --git a/components/precache/core/precache_fetcher.h b/components/precache/core/precache_fetcher.h
index d6c3fa416de693070e9605100bb8e6a027b4842f..24307b2a02fdd69f4b2d3b1135b6762ad280abc3 100644
--- a/components/precache/core/precache_fetcher.h
+++ b/components/precache/core/precache_fetcher.h
@@ -124,6 +124,9 @@ class PrecacheFetcher : public base::SupportsWeakPtr<PrecacheFetcher> {
   std::unique_ptr<PrecacheUnfinishedWork> CancelPrecaching();
 
  private:
+  friend class PrecacheFetcherTest;
+  FRIEND_TEST_ALL_PREFIXES(PrecacheFetcherTest, FetcherPoolMaxLimitReached);
+
   // Notifies the precache delete that precaching is done, and report
   // completion statistics.
   void NotifyDone(size_t remaining_manifest_urls_to_fetch,