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

chrome/browser/flag_descriptions.cc

 // Copyright 2017 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/flag_descriptions.h"
 
 namespace flag_descriptions {
 
 const char kBrowserSideNavigationName[] = "Enable browser side navigation";
 
@@ skipping 2909 matching lines @@
 
 const char kOfficeEditingComponentAppDescription[] =
     "Office Editing for Docs, Sheets & Slides for testing purposes.";
 
 const char kDisplayColorCalibrationName[] = "Color calibration of the display";
 
 const char kDisplayColorCalibrationDescription[] =
     "Allow color calibration of the display if the display supports the "
     "feature.";
 
+const char kEnableFullscreenAppListName[] = "Enable The Peeking Launcher";
+
+const char kEnableFullscreenAppListDescription[] =
+    "The peeking launcher UI supports touch and provides more space for upcoming "
+    "features.";
+
 const char kMemoryPressureThresholdName[] =
     "Memory discard strategy for advanced pressure handling";
 
 const char kMemoryPressureThresholdDescription[] =
     "Memory discarding strategy to use";
 
 const char kConservativeThresholds[] =
     "Conservative memory pressure release strategy";
 
 const char kAggressiveCacheDiscardThresholds[] =
@@ skipping 347 matching lines @@
     "in non-sticky mode (do not change work area in non-sticky mode).";
 
 const char kUiDevToolsName[] = "Enable native UI inspection";
 const char kUiDevToolsDescription[] =
     "Enables inspection of native UI elements. For local inspection use "
     "chrome://inspect#other";
 
 #endif  // defined(OS_CHROMEOS)
 
 }  // namespace flag_descriptions