Describe the histogram Net.QuicSession.PublicResetAddressMismatch.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
===================================================================
--- tools/metrics/histograms/histograms.xml	(revision 251851)
+++ tools/metrics/histograms/histograms.xml	(working copy)
@@ -9810,6 +9810,16 @@
   </summary>
 </histogram>
 
+<histogram name="Net.QuicSession.PublicResetAddressMismatch"
+    enum="QuicAddressMismatch">
+  <summary>
+    When a public reset packet is received, whether the client IP address and
+    port number in it differ from the client IP address and port number in the
+    ServerHello handshake message. In the comparison, the first address is the
+    one in ServerHello and the second address is the one in public reset.
+  </summary>
+</histogram>
+
 <histogram name="Net.QuicSession.QuicVersion">
   <summary>Version of the QUIC protocol used for this connection.</summary>
 </histogram>
@@ -30650,6 +30660,17 @@
   <int value="22" label="DOMAIN_NUM_EVENTS"/>
 </enum>
 
+<enum name="QuicAddressMismatch" type="int">
+  <int value="0" label="Address mismatch: IPv4 IPv4"/>
+  <int value="1" label="Address mismatch: IPv6 IPv6"/>
+  <int value="2" label="Address mismatch: IPv4 IPv6"/>
+  <int value="3" label="Address mismatch: IPv6 IPv4"/>
+  <int value="4" label="Port mismatch: IPv4 IPv4"/>
+  <int value="5" label="Port mismatch: IPv6 IPv6"/>
+  <int value="6" label="Address and port match: IPv4 IPv4"/>
+  <int value="7" label="Address and port match: IPv6 IPv6"/>
+</enum>
+
 <enum name="QuicErrorCodes" type="int">
   <int value="0" label="NO_ERROR"/>
   <int value="1" label="INTERNAL_ERROR"/>