predictors: Pass manifests from Bork to store in ResourcePrefetchPredictor.

components/precache/core/precache_fetcher_unittest.cc

Index: components/precache/core/precache_fetcher_unittest.cc
diff --git a/components/precache/core/precache_fetcher_unittest.cc b/components/precache/core/precache_fetcher_unittest.cc
index 4dda6bfa9fa10f309d91540f6ba59382e62be8bc..3ecf9b6e89deeb277acab16b20fa736a6ebae199 100644
--- a/components/precache/core/precache_fetcher_unittest.cc
+++ b/components/precache/core/precache_fetcher_unittest.cc
@@ -117,12 +117,18 @@ class TestPrecacheDelegate : public PrecacheFetcher::PrecacheDelegate {
     on_done_was_called_ = true;
   }
 
+  void OnManifestFetched(const std::string& host,
+                         const PrecacheManifest& manifest) override {
+    manifests_fetched.push_back(host);
+  }
+
   bool was_on_done_called() const {
     return on_done_was_called_;
   }
 
  private:
   bool on_done_was_called_;
+  std::vector<std::string> manifests_fetched;
 };
 
 class MockURLFetcherFactory : public net::URLFetcherFactory {