Add a new histogram Net.QuicSession.NetworkProbingResult which records network...

Add a new histogram Net.QuicSession.NetworkProbingResult which records network probing results according to different migration causes.

This is a temporary change in order to understand the success/failure
rate of network probings when attempting connection migration.

Change-Id: I3c4c64cec67322a23e39c22269bc3f44790a650b
Reviewed-on: https://chromium-review.googlesource.com/973912
Commit-Queue: Fan Yang <fayang@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Reviewed-by: Zhongyi Shi <zhongyi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546032}

net/quic/chromium/quic_chromium_client_session.cc

@@ -182,6 +182,9 @@ std::string ConnectionMigrationCauseToString(ConnectionMigrationCause cause) {
       return "OnMigrateBackToDefaultNetwork";
     case ON_PATH_DEGRADING:
       return "OnPathDegrading";
+    default:
+      QUIC_NOTREACHED();
+      break;
   }
   return "InvalidCause";
 }
@@ -213,6 +216,19 @@ std::unique_ptr<base::Value> NetLogQuicPushPromiseReceivedCallback(
   return std::move(dict);
 }
 
+// TODO(fayang): Remove this when necessary data is collected.
+void LogProbeResultToHistogram(ConnectionMigrationCause cause, bool success) {
+  UMA_HISTOGRAM_BOOLEAN("Net.QuicSession.ConnectionMigrationProbeSuccess",
+                        success);
+  const std::string histogram_name =
+      "Net.QuicSession.ConnectionMigrationProbeSuccess." +
+      ConnectionMigrationCauseToString(cause);
+  STATIC_HISTOGRAM_POINTER_GROUP(
+      histogram_name, cause, MIGRATION_CAUSE_MAX, AddBoolean(success),
+      base::BooleanHistogram::FactoryGet(
+          histogram_name, base::HistogramBase::kUmaTargetedHistogramFlag));
+}
+
 class HpackEncoderDebugVisitor : public QuicHpackDebugVisitor {
   void OnUseEntry(QuicTime::Delta elapsed) override {
     UMA_HISTOGRAM_TIMES(
@@ -1731,6 +1747,8 @@ void QuicChromiumClientSession::OnProbeNetworkSucceeded(
       NetLogEventType::QUIC_CONNECTION_CONNECTIVITY_PROBING_SUCCEEDED,
       NetLog::Int64Callback("network", network));
 
+  LogProbeResultToHistogram(current_connection_migration_cause_, true);
+
   // Set |this| to listen on socket write events on the packet writer
   // that was used for probing.
   writer->set_delegate(this);
@@ -1769,6 +1787,8 @@ void QuicChromiumClientSession::OnProbeNetworkFailed(
   net_log_.AddEvent(
       NetLogEventType::QUIC_CONNECTION_CONNECTIVITY_PROBING_FAILED,
       NetLog::Int64Callback("network", network));
+
+  LogProbeResultToHistogram(current_connection_migration_cause_, false);
   // Probing failure for default network can be ignored.
   DVLOG(1) << "Connectivity probing failed on NetworkHandle " << network;
   DVLOG_IF(1, network == default_network_ &&

net/quic/chromium/quic_chromium_client_session.h

@@ -90,6 +90,7 @@ enum ConnectionMigrationCause {
   ON_NETWORK_MADE_DEFAULT,             // With probing.
   ON_MIGRATE_BACK_TO_DEFAULT_NETWORK,  // With probing.
   ON_PATH_DEGRADING,                   // With probing.
+  MIGRATION_CAUSE_MAX
 };
 
 // Result of connection migration.

tools/metrics/histograms/histograms.xml

@@ -47644,6 +47644,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Net.QuicSession.ConnectionMigrationProbeSuccess"
+    enum="BooleanSuccess">
+  <owner>fayang@chromium.org</owner>
+  <summary>
+    The result of connectivity probing according to different migration causes.
+    Recorded for every connectivity probing when attempting connection
+    migrations.
+  </summary>
+</histogram>
+
 <histogram name="Net.QuicSession.ConnectionTypeFromPeer" enum="AddressFamily">
   <owner>rch@chromium.org</owner>
   <summary>
@@ -105851,6 +105861,7 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <suffix name="OnMigrateBackToDefaultNetwork"/>
   <suffix name="OnPathDegrading"/>
   <affected-histogram name="Net.QuicSession.ConnectionMigration"/>
+  <affected-histogram name="Net.QuicSession.ConnectionMigrationProbeSuccess"/>
 </histogram_suffixes>
 
 <histogram_suffixes name="ConnectivityDiagnostics" separator=".">