Add tcp connection time histograms.

Review URL: http://codereview.chromium.org/77036

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@13985 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 20 insertions, 0 deletions

diff --git a/net/http/http_network_transaction.cc b/net/http/http_network_transaction.cc
index aa5b691..1065729 100644
--- a/net/http/http_network_transaction.cc
+++ b/net/http/http_network_transaction.cc
@@ -595,6 +595,8 @@ int HttpNetworkTransaction::DoTCPConnect() {
 
   DCHECK(!connection_.socket());
 
+  connect_start_time_ = base::Time::Now();
+
   ClientSocket* s = socket_factory_->CreateTCPClientSocket(addresses_);
   connection_.set_socket(s);
   return connection_.socket()->Connect(&io_callback_);
@@ -604,6 +606,7 @@ int HttpNetworkTransaction::DoTCPConnectComplete(int result) {
   // If we are using a direct SSL connection, then go ahead and establish the
   // SSL connection, now.  Otherwise, we need to first issue a CONNECT request.
   if (result == OK) {
+    LogTCPConnectionMetrics();
     if (using_ssl_ && !using_tunnel_) {
       next_state_ = STATE_SSL_CONNECT;
     } else {
@@ -960,6 +963,17 @@ int HttpNetworkTransaction::DoDrainBodyForAuthRestartComplete(int result) {
   return OK;
 }
 
+void HttpNetworkTransaction::LogTCPConnectionMetrics() const {
+  DCHECK(connect_start_time_ != base::Time());
+  base::TimeDelta connect_duration =
+      base::Time::Now() - connect_start_time_;
+
+  UMA_HISTOGRAM_CLIPPED_TIMES(FieldTrial::MakeName(
+      "Net.TCP_Connection_Latency", "DnsImpact").data(), connect_duration,
+      base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(10),
+      100);
+}
+
 void HttpNetworkTransaction::LogTransactionConnectedMetrics() const {
   base::TimeDelta total_duration = response_.response_time - start_time_;
 
diff --git a/net/http/http_network_transaction.h b/net/http/http_network_transaction.h
index d41d29d..3915c7e 100644
--- a/net/http/http_network_transaction.h
+++ b/net/http/http_network_transaction.h
@@ -88,6 +88,9 @@ class HttpNetworkTransaction : public HttpTransaction {
   int DoDrainBodyForAuthRestart();
   int DoDrainBodyForAuthRestartComplete(int result);
 
+  // Record histogram of time to acquire a TCP connection.
+  void LogTCPConnectionMetrics() const;
+
   // Record histogram of time until first byte of header is received.
   void LogTransactionConnectedMetrics() const;
 
@@ -309,6 +312,9 @@ class HttpNetworkTransaction : public HttpTransaction {
   // The time the Start method was called.
   base::Time start_time_;
 
+  // The time the Connect() method was called (if it got called).
+  base::Time connect_start_time_;
+
   enum State {
     STATE_RESOLVE_PROXY,
     STATE_RESOLVE_PROXY_COMPLETE,