Report downloaded resources at most once

components/precache/core/precache_database.cc

Index: components/precache/core/precache_database.cc
diff --git a/components/precache/core/precache_database.cc b/components/precache/core/precache_database.cc
index 8650262a405707f64b27a55199c29dec8995cdb6..b742796d36c5abd97f872266842be487aef87e65 100644
--- a/components/precache/core/precache_database.cc
+++ b/components/precache/core/precache_database.cc
@@ -133,7 +133,7 @@ PrecacheReferrerHostEntry PrecacheDatabase::GetReferrerHost(
 void PrecacheDatabase::GetURLListForReferrerHost(
     int64_t referrer_host_id,
     std::vector<GURL>* used_urls,
-    std::vector<GURL>* unused_urls) {
+    std::vector<GURL>* downloaded_urls) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK_NE(PrecacheReferrerHostEntry::kInvalidId, referrer_host_id);
 
@@ -141,7 +141,8 @@ void PrecacheDatabase::GetURLListForReferrerHost(
   Flush();
 
   precache_url_table_.GetURLListForReferrerHost(referrer_host_id, used_urls,
-                                                unused_urls);
+                                                downloaded_urls);
+  precache_url_table_.SetDownloadReported(referrer_host_id);
 }
 
 void PrecacheDatabase::RecordURLPrefetchMetrics(
@@ -196,11 +197,12 @@ void PrecacheDatabase::RecordURLPrefetch(const GURL& url,
   // since it had no significant effect (besides a possible revalidation and a
   // change in the cache LRU priority). If a row for the URL already exists,
   // then the timestamp is updated.
+  const PrecacheURLInfo info = precache_url_table_.GetURLInfo(url);
   buffered_writes_.push_back(base::Bind(
       &PrecacheDatabase::RecordURLPrefetchInternal, GetWeakPtr(), url,
-      referrer_host,
-      !was_cached || precache_url_table_.GetURLInfo(url).is_precached,
-      fetch_time));
+      referrer_host, !was_cached || info.is_precached, fetch_time,
+      // Reset to 0 only if is_precached && !was_cached.
+      (!info.is_precached || was_cached) && info.is_download_reported));

[twifkak, 2016/12/20 22:48:09]

Perhaps extract this logic to be more readable:

bool is_download_reported = info.is_download_reported;
// Reset to false if a new prefetch occurred:
if (info.is_precached && !was_cached)
  is_download_reported = false;

[jamartin, 2016/12/20 23:14:07]

Done.

   buffered_urls_.insert(url.spec());
   MaybePostFlush();
 }
@@ -209,7 +211,8 @@ void PrecacheDatabase::RecordURLPrefetchInternal(
     const GURL& url,
     const std::string& referrer_host,
     bool is_precached,
-    const base::Time& fetch_time) {
+    const base::Time& fetch_time,
+    bool is_download_reported) {
   int64_t referrer_host_id =
       precache_referrer_host_table_.GetReferrerHost(referrer_host).id;
   if (referrer_host_id == PrecacheReferrerHostEntry::kInvalidId) {
@@ -217,7 +220,8 @@ void PrecacheDatabase::RecordURLPrefetchInternal(
         referrer_host, 0, fetch_time);
   }
   DCHECK_NE(referrer_host_id, PrecacheReferrerHostEntry::kInvalidId);
-  precache_url_table_.AddURL(url, referrer_host_id, is_precached, fetch_time);
+  precache_url_table_.AddURL(url, referrer_host_id, is_precached, fetch_time,
+                             is_download_reported);
 }
 
 void PrecacheDatabase::RecordURLNonPrefetch(const GURL& url,
@@ -337,6 +341,7 @@ void PrecacheDatabase::UpdatePrecacheReferrerHostInternal(
     const base::Time& fetch_time) {
   int64_t referrer_host_id = precache_referrer_host_table_.UpdateReferrerHost(
       hostname, manifest_id, fetch_time);
+
   if (referrer_host_id != PrecacheReferrerHostEntry::kInvalidId) {
     precache_url_table_.ClearAllForReferrerHost(referrer_host_id);
   }