NetLog the SPN used for integrated authentication on Windows.

A similar change is not needed for POSIX platforms, as they log the SPN as part of the AUTH_LIBRARY_IMPORT_NAME event.

Bug: 924746
Change-Id: I8cc1c8e5fb95334fa3ad078adeac3dff96f8d0ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2227176
Commit-Queue: Eric Roman <eroman@chromium.org>
Reviewed-by: Asanka Herath <asanka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774856}

net/http/http_auth_sspi_win.cc

@@ -547,7 +547,12 @@ int HttpAuthSSPI::GetNextSecurityToken(const std::string& spn,
   if (delegation_type_ != DelegationType::kNone)
     context_flags |= (ISC_REQ_DELEGATE | ISC_REQ_MUTUAL_AUTH);
 
-  net_log.BeginEvent(NetLogEventType::AUTH_LIBRARY_INIT_SEC_CTX);
+  net_log.BeginEvent(NetLogEventType::AUTH_LIBRARY_INIT_SEC_CTX, [&] {
+    base::Value params{base::Value::Type::DICTIONARY};
+    params.SetStringKey("spn", spn);
+    params.SetKey("flags", ContextFlagsToValue(context_flags));
+    return params;
+  });
 
   // This returns a token that is passed to the remote server.
   DWORD context_attributes = 0;

net/http/http_auth_sspi_win_unittest.cc

@@ -258,6 +258,18 @@ TEST(HttpAuthSSPITest, GenerateAuthToken_FullHandshake_AmbientCreds_Logging) {
       net_log.GetEntriesWithType(NetLogEventType::AUTH_LIBRARY_INIT_SEC_CTX);
   ASSERT_EQ(4u, entries.size());
 
+  expected = base::JSONReader::Read(R"(
+    {
+       "flags": {
+          "delegated": false,
+          "mutual": false,
+          "value": "0x00000000"
+       },
+       "spn": "HTTP/intranet.google.com"
+    }
+  )");
+  EXPECT_EQ(expected, entries[0].params);
+
   expected = base::JSONReader::Read(R"(
     {
       "context": {

net/log/net_log_event_type_list.h

@@ -2658,13 +2658,21 @@ EVENT_TYPE(AUTH_LIBRARY_ACQUIRE_CREDS)
 // This operation involves invoking an external library which may perform disk,
 // IPC, and network IO as a part of its work.
 //
-// On Posix platforms, the END phase has the following parameters.
+// On Windows, the BEGIN phase has the following parameters:
+//   {
+//     "spn": <Service Principle Name>,
+//     "context_flags": <Integer with bitfield value>
+//   }
+//
+// The END phase has the following parameters.
+//
+// On Posix platforms:
 //   {
 //     "context": <GSSAPI Context Description>,
 //     "status" : <GSSAPI Status if the operation failed>
 //   }
 //
-// On Windows, the END phase has the following parameters.
+// On Windows:
 //   {
 //     "context": <SSPI Context Description>
 //     "status" : <SSPI SECURITY_STATUS>