Added flag in chrome://flags to enable the New Launcher UI.

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 1421 matching lines @@
         flag_descriptions::kOfficeEditingComponentAppDescription, kOsCrOS,
         SINGLE_DISABLE_VALUE_TYPE(
             chromeos::switches::kDisableOfficeEditingComponentApp),
     },
     {
         "disable-display-color-calibration",
         flag_descriptions::kDisplayColorCalibrationName,
         flag_descriptions::kDisplayColorCalibrationDescription, kOsCrOS,
         SINGLE_DISABLE_VALUE_TYPE(::switches::kDisableDisplayColorCalibration),
     },
+    {
+        "new-app-list-ui", flag_descriptions::kEnableNewAppListUIName,
+        flag_descriptions::kEnableNewAppListUIDescription, kOsCrOS,
+        SINGLE_VALUE_TYPE(app_list::switches::kEnableNewAppListUI),

[stevenjb, 2017/06/30 21:17:25]

Is there a better descriptor here than "new"?

[newcomer, 2017/06/30 21:40:23]

Fixed.

+    },
     {"instant-tethering", flag_descriptions::kTetherName,
      flag_descriptions::kTetherDescription, kOsCrOS,
      FEATURE_VALUE_TYPE(features::kInstantTethering)},
 #endif  // OS_CHROMEOS
     {
         "disable-accelerated-video-decode",
         flag_descriptions::kAcceleratedVideoDecodeName,
         flag_descriptions::kAcceleratedVideoDecodeDescription,
         kOsMac | kOsWin | kOsCrOS | kOsAndroid,
         SINGLE_DISABLE_VALUE_TYPE(switches::kDisableAcceleratedVideoDecode),
@@ skipping 1877 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags