3 files changed, 57 insertions, 13 deletions

diff --git a/chrome/browser/browser_main.cc b/chrome/browser/browser_main.cc
index 0ffe724..f4e139b 100644
--- a/chrome/browser/browser_main.cc
+++ b/chrome/browser/browser_main.cc
@@ -60,6 +60,7 @@
 #include "net/base/cookie_monster.h"
 #include "net/base/net_module.h"
 #include "net/http/http_network_session.h"
+#include "net/socket/client_socket_pool_base.h"
 
 #if defined(OS_POSIX)
 // TODO(port): get rid of this include. It's used just to provide declarations
@@ -629,6 +630,14 @@ int BrowserMain(const MainFunctionParams& parameters) {
     ResourceDispatcherHost::DisableHttpPrioritization();
   }
 
+  scoped_refptr<FieldTrial> socket_late_binding_trial =
+      new FieldTrial("SocketLateBinding", 100);
+  socket_late_binding_trial->AppendGroup("_disable_late_binding", 50);
+  const int late_binding_group =
+      socket_late_binding_trial->AppendGroup("_enable_late_binding", 50);
+  if (socket_late_binding_trial->group() == late_binding_group)
+    net::ClientSocketPoolBase::EnableLateBindingOfSockets(true);
+
 #if defined(OS_WIN)
   // Init common control sex.
   INITCOMMONCONTROLSEX config;
diff --git a/net/http/http_network_transaction.cc b/net/http/http_network_transaction.cc
index f705541..0ccaf79 100644
--- a/net/http/http_network_transaction.cc
+++ b/net/http/http_network_transaction.cc
@@ -617,6 +617,8 @@ int HttpNetworkTransaction::DoInitConnection() {
     resolve_info.set_allow_cached_response(false);
   }
 
+  transport_socket_request_time_ = base::TimeTicks::Now();
+
   int rv = connection_.Init(connection_group, resolve_info, request_->priority,
                             &io_callback_);
   return rv;
@@ -632,12 +634,12 @@ int HttpNetworkTransaction::DoInitConnectionComplete(int result) {
   // connection.  This flag is used to handle errors that occur while we are
   // trying to reuse a keep-alive connection.
   reused_socket_ = connection_.is_reused();
+  LogTCPConnectedMetrics(reused_socket_);
   if (reused_socket_) {
     next_state_ = STATE_WRITE_HEADERS;
   } else {
     // Now we have a TCP connected socket.  Perform other connection setup as
     // needed.
-    LogTCPConnectedMetrics();
     if (proxy_mode_ == kSOCKSProxy)
       next_state_ = STATE_SOCKS_CONNECT;
     else if (using_ssl_ && proxy_mode_ == kDirectConnection) {
@@ -1085,20 +1087,40 @@ int HttpNetworkTransaction::DoDrainBodyForAuthRestartComplete(int result) {
   return OK;
 }
 
-void HttpNetworkTransaction::LogTCPConnectedMetrics() const {
-  base::TimeDelta host_resolution_and_tcp_connection_latency =
-      base::Time::Now() - host_resolution_start_time_;
+void HttpNetworkTransaction::LogTCPConnectedMetrics(bool reused_socket) const {
+  base::TimeDelta time_to_obtain_connected_socket =
+      base::TimeTicks::Now() - transport_socket_request_time_;
+
+  if (!reused_socket) {
+    UMA_HISTOGRAM_CLIPPED_TIMES(
+        "Net.Dns_Resolution_And_TCP_Connection_Latency",
+        time_to_obtain_connected_socket,
+        base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(10),
+        100);
+
+    UMA_HISTOGRAM_COUNTS_100(
+        "Net.TCP_Connection_Idle_Sockets",
+        session_->connection_pool()->IdleSocketCountInGroup(
+            connection_.group_name()));
+  }
 
   UMA_HISTOGRAM_CLIPPED_TIMES(
-      "Net.Dns_Resolution_And_TCP_Connection_Latency",
-      host_resolution_and_tcp_connection_latency,
+      "Net.TransportSocketRequestTime",
+      time_to_obtain_connected_socket,
       base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(10),
       100);
 
-  UMA_HISTOGRAM_COUNTS_100(
-      "Net.TCP_Connection_Idle_Sockets",
-      session_->connection_pool()->IdleSocketCountInGroup(
-          connection_.group_name()));
+  static const bool use_late_binding_histogram =
+      !FieldTrial::MakeName("", "SocketLateBinding").empty();
+
+  if (use_late_binding_histogram) {
+    UMA_HISTOGRAM_CUSTOM_TIMES(
+        FieldTrial::MakeName("Net.TransportSocketRequestTime",
+                             "SocketLateBinding").data(),
+        time_to_obtain_connected_socket,
+        base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(10),
+        100);
+  }
 }
 
 void HttpNetworkTransaction::LogTransactionConnectedMetrics() const {
@@ -1109,6 +1131,19 @@ void HttpNetworkTransaction::LogTransactionConnectedMetrics() const {
       total_duration,
       base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(10),
       100);
+
+  static const bool use_late_binding_histogram =
+      !FieldTrial::MakeName("", "SocketLateBinding").empty();
+
+  if (use_late_binding_histogram) {
+    UMA_HISTOGRAM_CUSTOM_TIMES(
+        FieldTrial::MakeName("Net.Transaction_Connected_Under_10",
+                             "SocketLateBinding").data(),
+        total_duration,
+        base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(10),
+        100);
+  }
+
   if (!reused_socket_)
     UMA_HISTOGRAM_CLIPPED_TIMES(
         "Net.Transaction_Connected_New",
diff --git a/net/http/http_network_transaction.h b/net/http/http_network_transaction.h
index 63ac243..83524c4 100644
--- a/net/http/http_network_transaction.h
+++ b/net/http/http_network_transaction.h
@@ -153,7 +153,7 @@ class HttpNetworkTransaction : public HttpTransaction {
   int DoDrainBodyForAuthRestartComplete(int result);
 
   // Record histograms of latency until Connect() completes.
-  void LogTCPConnectedMetrics() const;
+  void LogTCPConnectedMetrics(bool reused_socket) const;
 
   // Record histogram of time until first byte of header is received.
   void LogTransactionConnectedMetrics() const;
@@ -394,8 +394,8 @@ class HttpNetworkTransaction : public HttpTransaction {
   // The time the Connect() method was called (if it got called).
   base::Time connect_start_time_;
 
-  // The time the host resolution started (if it indeed got started).
-  base::Time host_resolution_start_time_;
+  // The time that we request the ClientSocketPool for a connected socket.
+  base::TimeTicks transport_socket_request_time_;
 
   // The next state in the state machine.
   State next_state_;