QUIC - disable QUIC if packet loss rate is bad for a connection.

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 4d36619ab5c661fca1ebe7526473152b376d5933..6160c2de4ed61fb60eb8a82b0b435bcd8feeda25 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -19457,6 +19457,16 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Net.QuicSession.HasBadPacketLossRate"
+    enum="BooleanHasBadPacketLossRate">
+  <owner>rtenneti@chromium.org</owner>
+  <summary>
+    Whether the connection has high packet loss rate or not when cryto handshake
+    is completed. This is logged only when packet loss rate goes above a packet
+    loss threshold parameter.
+  </summary>
+</histogram>
+
 <histogram name="Net.QuicSession.HeadersStream.EarlyFramesReceived">
   <owner>rch@chromium.org</owner>
   <summary>
@@ -19791,6 +19801,14 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Net.QuicStreamFactory.QuicIsDisabled" enum="Boolean">
+  <owner>rtenneti@chromium.org</owner>
+  <summary>
+    Recorded whenever QUIC is disabled due to high packet loss rate and when
+    number of lossy connections goes over a threshold.
+  </summary>
+</histogram>
+
 <histogram name="Net.QuicVerifyProofFailed.HandshakeConfirmed"
     enum="BooleanHandshakeConfirmed">
   <owner>rtenneti@chromium.org</owner>
@@ -45356,6 +45374,11 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="1" label="Hardware accelerated"/>
 </enum>
 
+<enum name="BooleanHasBadPacketLossRate" type="int">
+  <int value="0" label="Not high packet loss"/>
+  <int value="1" label="High packet loss"/>
+</enum>
+
 <enum name="BooleanHasCrc" type="int">
   <int value="0" label="No CRC"/>
   <int value="1" label="Has CRC"/>