precache: Fix top_resources_count + experiments.

components/precache/core/precache_fetcher.cc

Index: components/precache/core/precache_fetcher.cc
diff --git a/components/precache/core/precache_fetcher.cc b/components/precache/core/precache_fetcher.cc
index 0bc2e1b2b40cb1e2c17a5bfdf84000c00aec1a08..56bec9ff45e51de96cb826022eb24b552dd94dcb 100644
--- a/components/precache/core/precache_fetcher.cc
+++ b/components/precache/core/precache_fetcher.cc
@@ -743,12 +743,13 @@ void PrecacheFetcher::OnManifestFetchComplete(int64_t host_visits,
     PrecacheManifest manifest;
 
     if (ParseProtoFromFetchResponse(*source.network_url_fetcher(), &manifest)) {
-      const int32_t len =
-          std::min(manifest.resource_size(),
-                   unfinished_work_->config_settings().top_resources_count());
       const uint64_t resource_bitset =
           GetResourceBitset(manifest, experiment_id_);
-      for (int i = 0; i < len; ++i) {
+      const int32_t max_to_include =
+          unfinished_work_->config_settings().top_resources_count();
+      int32_t num_included = 0;
+      for (int i = 0;
+           i < manifest.resource_size() && num_included < max_to_include; ++i) {
         if (((0x1ULL << i) & resource_bitset) &&
             manifest.resource(i).has_url()) {
           GURL url(manifest.resource(i).url());
@@ -756,8 +757,10 @@ void PrecacheFetcher::OnManifestFetchComplete(int64_t host_visits,
             double weight = ResourceWeight(
                 unfinished_work_->config_settings().resource_weight_function(),
                 manifest.resource(i).weight_ratio(), host_visits);
-            if (weight >= unfinished_work_->config_settings().min_weight())
+            if (weight >= unfinished_work_->config_settings().min_weight()) {
               resources_to_rank_.emplace_back(url, source.referrer(), weight);
+              ++num_included;

[bengr, 2017/02/24 21:04:13]

nit: I would be a bit clearer:
num_included -> included_resources_count
max_to_include -> maximum_included_resources_count
I'd also be ok with dropping the _count suffix.

[twifkak, 2017/02/24 21:35:55]

Done.

+            }
           }
         }
       }