IPv6 related 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 57cf2870374239a36267d9e56c954da44c72c716..df3e4f16725ea94fdb5da00fabcf66393d58b01b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -18653,6 +18653,24 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Network.Shill.Cellular.IPv6ConnectivityStatus"
+    enum="IPv6ConnectivityStatus">
+  <owner>zqiu@chromium.org</owner>
+  <summary>
+    Chrome OS network metric that tracks the presence of complete IPv6
+    configuration at the time when cellular connection is established.
+  </summary>
+</histogram>
+
+<histogram name="Network.Shill.Cellular.NetworkConnectionIPType"
+    enum="NetworkConnectionIPType">
+  <owner>zqiu@chromium.org</owner>
+  <summary>
+    Chrome OS network metric that tracks the types of IP configuration used for
+    establishing cellular connections.
+  </summary>
+</histogram>
+
 <histogram name="Network.Shill.Cellular.OutOfCreditsReason"
     enum="NetworkCellularOutOfCreditsReason">
   <owner>quiche@chromium.org</owner>
@@ -19219,6 +19237,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Network.Shill.Wifi.IPv6ConnectivityStatus"
+    enum="IPv6ConnectivityStatus">
+  <owner>zqiu@chromium.org</owner>
+  <summary>
+    Chrome OS network metric that tracks the presence of complete IPv6
+    configuration at the time when WiFi connection is established.
+  </summary>
+</histogram>
+
 <histogram name="Network.Shill.Wifi.LinkMonitorBroadcastErrorsAtFailure">
   <owner>quiche@chromium.org</owner>
   <summary>
@@ -19264,6 +19291,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Network.Shill.Wifi.NetworkConnectionIPType"
+    enum="NetworkConnectionIPType">
+  <owner>zqiu@chromium.org</owner>
+  <summary>
+    Chrome OS network metric that tracks the types of IP configuration used for
+    establishing WiFi connections.
+  </summary>
+</histogram>
+
 <histogram name="Network.Shill.Wifi.NetworkProblemDetected"
     enum="NetworkProblemType">
   <owner>zqiu@chromium.org</owner>
@@ -43412,6 +43448,11 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="1" label="GCMNetworkChannel"/>
 </enum>
 
+<enum name="IPv6ConnectivityStatus" type="int">
+  <int value="0" label="Incomplete IPv6 Configuration"/>
+  <int value="1" label="Complete IPv6 Configuration"/>
+</enum>
+
 <enum name="IPV6ProbeResult" type="int">
   <int value="0" label="IPV6_CANNOT_CREATE_SOCKETS"/>
   <int value="1" label="IPV6_CAN_CREATE_SOCKETS"/>
@@ -45960,6 +46001,11 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="42" label="5230"/>
 </enum>
 
+<enum name="NetworkConnectionIPType" type="int">
+  <int value="0" label="IPv4"/>
+  <int value="1" label="IPv6"/>
+</enum>
+
 <enum name="NetworkCorruptedProfile" type="int">
   <int value="0" label="Corrupted Profile"/>
 </enum>