QUIC - Track the reason for sending InchoateClientHello in UMA

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 316fca0710846a55b33f734779e133b9d8726142..6465e7e3635a111ac1ed8fe66ebdb80fc573567c 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -14919,6 +14919,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Net.QuicClientHelloServerConfigState"
+    enum="QuicServerConfigState">
+  <owner>rtenneti@chromium.org</owner>
+  <summary>
+    The reason (the state of the server config) for sending InchoateClientHello
+    to the server.
+  </summary>
+</histogram>
+
 <histogram name="Net.QuicEphemeralPortsSuggested">
   <owner>rch@chromium.org</owner>
   <summary>The number of ports suggested per server.</summary>
@@ -45903,6 +45912,13 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="6" label="CANCELLED"/>
 </enum>
 
+<enum name="QuicServerConfigState" type="int">
+  <int value="0" label="SERVER_CONFIG_EMPTY"/>
+  <int value="1" label="SERVER_CONFIG_INVALID"/>
+  <int value="2" label="SERVER_CONFIG_CORRUPTED"/>
+  <int value="3" label="SERVER_CONFIG_EXPIRED"/>
+</enum>
+
 <enum name="QuicSessionErrorCodes" type="int">
   <int value="0" label="CONNECTING_SOCKET"/>
   <int value="1" label="SETTING_RECEIVE_BUFFER"/>