Add histogram to show network latency (first byte to last byte)

Also added a histogram to show effective bandwidth of the download.

r=darin,wtc
Review URL: http://codereview.chromium.org/9625

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@4898 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 16 insertions, 0 deletions

diff --git a/net/http/http_network_transaction.cc b/net/http/http_network_transaction.cc
index 8e947f57..ae82b67 100644
--- a/net/http/http_network_transaction.cc
+++ b/net/http/http_network_transaction.cc
@@ -757,6 +757,7 @@ int HttpNetworkTransaction::DoReadBodyComplete(int result) {
 
   // Clean up the HttpConnection if we are done.
   if (done) {
+    LogTransactionMetrics();
     if (!keep_alive)
       connection_.set_socket(NULL);
     connection_.Reset();
@@ -770,6 +771,17 @@ int HttpNetworkTransaction::DoReadBodyComplete(int result) {
   return result;
 }
 
+void HttpNetworkTransaction::LogTransactionMetrics() const {
+  base::TimeDelta duration = base::Time::Now() - response_.request_time;
+  if (60 < duration.InMinutes())
+    return;
+  UMA_HISTOGRAM_LONG_TIMES(L"Net.Transaction_Latency", duration);
+  if (!duration.InMilliseconds())
+    return;
+  UMA_HISTOGRAM_COUNTS(L"Net.Transaction_Bandwidth",
+      static_cast<int> (content_read_ / duration.InMilliseconds()));
+}
+
 int HttpNetworkTransaction::DidReadResponseHeaders() {
   scoped_refptr<HttpResponseHeaders> headers;
   if (has_found_status_line_start()) {
diff --git a/net/http/http_network_transaction.h b/net/http/http_network_transaction.h
index dc850b5..2f733389 100644
--- a/net/http/http_network_transaction.h
+++ b/net/http/http_network_transaction.h
@@ -77,6 +77,10 @@ class HttpNetworkTransaction : public HttpTransaction {
   int DoReadBody();
   int DoReadBodyComplete(int result);
 
+  // Record histogram of latency (first byte sent till last byte received) as
+  // well as effective bandwidth used.
+  void LogTransactionMetrics() const;
+
   // Called when header_buf_ contains the complete response headers.
   int DidReadResponseHeaders();