Add SBClientDownload.DownloadRequestNetworkDuration and DownloadRequestTimeoutDuration histograms.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 916791252a78aab5aef79c2dac1a06fdd6ef2d5f..b79248543c50cf2f7db7ec0db1c7ad9aab59810b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -23437,8 +23437,11 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <owner>mattm@chromium.org</owner>
   <summary>
     Records the total time it takes for the SafeBrowsing download service to
-    check whether the content of a download is malicious or not. This histogram
-    only includes requests that are sent to the SafeBrowsing server.
+    check whether the content of a download is malicious or not, including file
+    feature extraction, whitelist checking, and server ping. This histogram only
+    includes checks that sent a ping to the SafeBrowsing server. It does not
+    include requests that were cancelled, but does include requests that
+    received a bad response.
   </summary>
 </histogram>
 
@@ -23449,6 +23452,24 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="SBClientDownload.DownloadRequestNetworkDuration"
+    units="milliseconds">
+  <owner>mattm@chromium.org</owner>
+  <summary>
+    Records the time it takes for the SafeBrowsing download service ping. It is
+    not recorded for requests that were cancelled.
+  </summary>
+</histogram>
+
+<histogram name="SBClientDownload.DownloadRequestNetworkStats"
+    enum="SBClientDownloadCheckDownloadStats">
+  <owner>mattm@chromium.org</owner>
+  <summary>
+    Records the results of SafeBrowsing binary download checks which caused a
+    server ping.
+  </summary>
+</histogram>
+
 <histogram name="SBClientDownload.DownloadRequestPayloadSize" units="bytes">
   <owner>mattm@chromium.org</owner>
   <summary>
@@ -23464,6 +23485,26 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="SBClientDownload.DownloadRequestTimeoutDuration"
+    units="milliseconds">
+  <owner>mattm@chromium.org</owner>
+  <summary>
+    Records the portion of the SafeBrowsing download service check starting with
+    the point CheckClientDownloadRequest::StartTimeout() is called. It is
+    recorded regardless if a ping was sent or not. It is not recorded for
+    requests that were cancelled.
+  </summary>
+</histogram>
+
+<histogram name="SBClientDownload.DownloadRequestTimeoutStats"
+    enum="SBClientDownloadCheckDownloadStats">
+  <owner>mattm@chromium.org</owner>
+  <summary>
+    Records the results of SafeBrowsing binary download checks which reached the
+    CheckClientDownloadRequest::StartTimeout() call.

[Mark P, 2014/06/05 00:28:55]

You might want to clarify that this not recorded at the time of the StartTimeout
call, but recorded later once we know if (for instance) a resulting ping
received a reply.

[mattm, 2014/06/05 01:23:55]

Done.

+  </summary>
+</histogram>
+
 <histogram name="SBClientDownload.ExtractImageHeadersTime" units="milliseconds">
   <owner>grt@chromium.org</owner>
   <summary>