Restrict total parallel DNS resolutions

A/B tests suggest that large numbers of parallel
resolutions may cause the DNS failure rate
(re: ratio of "host not found" to "found") to
rise.  To stay safely away from that threshold,
this change lowers the maximum parallel resolutions
to 8, and restricts the speculative resolutions
to 3.

We are also running A/B tests which will look at the
impact of modulating either of these values.

BUG=3041
r=eroman
Review URL: http://codereview.chromium.org/4111004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@64369 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 3 insertions, 4 deletions

diff --git a/chrome/browser/io_thread.h b/chrome/browser/io_thread.h
index 2baec87..09f4df4 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -61,7 +61,7 @@ class IOThread : public BrowserProcessSubThread {
   // It will post a task to the IO thread to perform the actual initialization.
   void InitNetworkPredictor(bool prefetching_enabled,
                             base::TimeDelta max_dns_queue_delay,
-                            size_t max_concurrent,
+                            size_t max_speculative_parallel_resolves,
                             const chrome_common_net::UrlList& startup_urls,
                             ListValue* referral_list,
                             bool preconnect_enabled);
@@ -92,9 +92,8 @@ class IOThread : public BrowserProcessSubThread {
   void InitNetworkPredictorOnIOThread(
       bool prefetching_enabled,
       base::TimeDelta max_dns_queue_delay,
-      size_t max_concurrent,
-        const chrome_common_net::UrlList& startup_urls,
-
+      size_t max_speculative_parallel_resolves,
+      const chrome_common_net::UrlList& startup_urls,
       ListValue* referral_list,
       bool preconnect_enabled);