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

chrome/browser/flag_descriptions.cc

Index: chrome/browser/flag_descriptions.cc
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 27a963351a282e3426826dd9d3f41ea2e2e118bd..f75d61fdf60810d916387983a222b2e2cd58d88f 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -2927,6 +2927,12 @@ 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";