[Not for review] Add TRACE_EVENTs and chrome://flags for preconnect

chrome/browser/about_flags.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 1467 matching lines @@
          password_manager::features::kEnablePasswordForceSaving)},
     {"enable-manual-password-generation",
      flag_descriptions::kManualPasswordGenerationName,
      flag_descriptions::kManualPasswordGenerationDescription, kOsAll,
      FEATURE_VALUE_TYPE(
          password_manager::features::kEnableManualPasswordGeneration)},
     {"enable-show-autofill-signatures",
      flag_descriptions::kShowAutofillSignaturesName,
      flag_descriptions::kShowAutofillSignaturesDescription, kOsAll,
      SINGLE_VALUE_TYPE(autofill::switches::kShowAutofillSignatures)},
+
+    {"enable-predictor-preconnect", flag_descriptions::kPredictorPreconnectName,
+     flag_descriptions::kPredictorPreconnectDescription, kOsAll,
+     FEATURE_VALUE_TYPE(features::kPredictorPreconnect)},
+
     {"affiliation-based-matching",
      flag_descriptions::kAffiliationBasedMatchingName,
      flag_descriptions::kAffiliationBasedMatchingDescription, kOsAll,
      FEATURE_VALUE_TYPE(password_manager::features::kAffiliationBasedMatching)},
     {"wallet-service-use-sandbox",
      flag_descriptions::kWalletServiceUseSandboxName,
      flag_descriptions::kWalletServiceUseSandboxDescription,
      kOsAndroid | kOsDesktop,
      ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(
          autofill::switches::kWalletServiceUseSandbox,
@@ skipping 1738 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags