Add histograms for DHCP lease expiry

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 c63891fb76ecacfc4851cb2c32196e7bb638dbb4..c2b47d69f053d9b524472f7fd5ccedfd7de76142 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -2311,7 +2311,7 @@ other types of suffix sets.
 <histogram name="DNS.IndependentFailedNavigation" units="milliseconds">
   <summary>
     When either a pre-resolution was not done recently enough to provide
-    benefit, or the the corresponding pre-resolution is still pending, this
+    benefit, or the corresponding pre-resolution is still pending, this
     histogram shows the duration of time used to resolve a hostname as not
     existing during a failed attempt to navigate to (GET) a URL.  In newer
     versions, if the hostname has never been found as a link during a page scan,
@@ -2323,7 +2323,7 @@ other types of suffix sets.
 <histogram name="DNS.IndependentNavigation" units="milliseconds">
   <summary>
     When either a pre-resolution was not done recently enough to provide
-    benefit, or the the corresponding pre-resolution is still pending, this
+    benefit, or the corresponding pre-resolution is still pending, this
     histogram shows the duration of the duration of time used to resolve a
     hostname to navigate to (GET) a URL.  In newer versions, if the hostname has
     never been found as a link during a page scan, and it has a referring URL,
@@ -8752,14 +8752,14 @@ other types of suffix sets.
 
 <histogram name="Net.IPv6ConnectFailureMatch" enum="BooleanSuccess">
   <summary>
-    Whether the the interface-enumeration IPv6 probe method failed given that
-    the UDP-connect IPV6 probe failed.
+    Whether the interface-enumeration IPv6 probe method failed given that the
+    UDP-connect IPV6 probe failed.
   </summary>
 </histogram>
 
 <histogram name="Net.IPv6ConnectSuccessMatch" enum="BooleanSuccess">
   <summary>
-    Whether the the interface-enumeration IPv6 probe method was successful given
+    Whether the interface-enumeration IPv6 probe method was successful given
     that the UDP-connect IPV6 probe was successful.
   </summary>
 </histogram>
@@ -9723,8 +9723,8 @@ other types of suffix sets.
 
 <histogram name="Net.SpdyStreamDownloadTime" units="milliseconds">
   <summary>
-    The time between receiving the the first chunk and the last chunk of data on
-    a Spdy stream.
+    The time between receiving the first chunk and the last chunk of data on a
+    Spdy stream.
   </summary>
 </histogram>
 
@@ -10825,6 +10825,15 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="Network.Shill.Cellular.ExpiredLeaseLengthSeconds"
+    units="seconds">
+  <summary>
+    Chrome OS network performance metric that tracks the length of a lease for a
+    cellular network at the time it expired without the DHCP client being able
+    to renew it.
+  </summary>
+</histogram>
+
 <histogram name="Network.Shill.Cellular.OutOfCreditsReason"
     enum="NetworkCellularOutOfCreditsReason">
   <summary>
@@ -10953,6 +10962,15 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="Network.Shill.Ethernet.ExpiredLeaseLengthSeconds"
+    units="seconds">
+  <summary>
+    Chrome OS network performance metric that tracks the length of a lease for
+    an Ethernet network at the time it expired without the DHCP client being
+    able to renew it.
+  </summary>
+</histogram>
+
 <histogram name="Network.Shill.Ethernet.LinkMonitorBroadcastErrorsAtFailure">
   <summary>
     Chrome OS network performance metric that tracks the number of LinkMonitor
@@ -11222,6 +11240,14 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="Network.Shill.Wifi.ExpiredLeaseLengthSeconds" units="seconds">
+  <summary>
+    Chrome OS network performance metric that tracks the length of a lease for a
+    WiFi network at the time it expired without the DHCP client being able to
+    renew it.
+  </summary>
+</histogram>
+
 <histogram name="Network.Shill.WiFi.FrequenciesConnectedEver">
   <summary>
     Chrome OS metric sampling the number of different frequencies (i.e.
@@ -11418,6 +11444,14 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="Network.Shill.WiMax.ExpiredLeaseLengthSeconds" units="seconds">
+  <summary>
+    Chrome OS network performance metric that tracks the length of a lease for a
+    WiMax network at the time it expired without the DHCP client being able to
+    renew it.
+  </summary>
+</histogram>
+
 <histogram name="Network.Shill.WiMax.TimeToConfig" units="milliseconds">
   <summary>
     Chrome OS network performance metric sampling the time to configure Layer 3
@@ -12249,9 +12283,8 @@ other types of suffix sets.
   <summary>
     When a client resumes a download, the HTTP request includes range specifier
     to skip the bytes it already has. This metric conveys this as a percentage
-    of the the file size.  This is reported every time a file is served, even if
-    the request does not include a range specifier (in which case 0 is
-    reported).
+    of the file size.  This is reported every time a file is served, even if the
+    request does not include a range specifier (in which case 0 is reported).
   </summary>
 </histogram>
 
@@ -12279,8 +12312,8 @@ other types of suffix sets.
 
 <histogram name="PasswordManager.AccountsPerSite">
   <summary>
-    The number of accounts stored per site in the the password manager (one
-    event per site)
+    The number of accounts stored per site in the password manager (one event
+    per site)
   </summary>
 </histogram>
 
@@ -13812,8 +13845,8 @@ other types of suffix sets.
     Perceived load time of a prerendered page that is displayed. This is the
     time from when the prerendered page is moved into a TabContents until
     finish. &quot;Finish&quot; == after onload() and all resources are loaded.
-    Note that this is 0 if the loading finishes before the the page is moved
-    into a TabContents.
+    Note that this is 0 if the loading finishes before the page is moved into a
+    TabContents.
   </summary>
 </histogram>
 
@@ -14852,7 +14885,7 @@ other types of suffix sets.
     the renderer process. This is the time from when the prerendered page is
     moved into a TabContents until finish. &quot;Finish&quot; == after onload()
     and all resources are loaded. Note that this is 0 if the loading finishes
-    before the the page is moved into a TabContents.
+    before the page is moved into a TabContents.
   </summary>
 </histogram>