Added flag --enable-new-app-list-mixer.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index c168a7baee418b946ae451d19af2515f0da2b0c3..52ab49d109a29c7227f5c4edb352b2f4723faa99 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -56360,6 +56360,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="884106779" label="supervised-user-safesites"/>
   <int value="887011602" label="enable-spelling-auto-correct"/>
   <int value="909439558" label="disable-device-discovery"/>
+  <int value="916316159" label="disable-new-app-list-mixer"/>
   <int value="929462705" label="disable-link-disambiguation-popup"/>
   <int value="936919953" label="bypass-app-banner-engagement-checks"/>
   <int value="939554480" label="enable-credit-card-scan"/>
@@ -56462,6 +56463,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="1783293530" label="disallow-autofill-sync-credential"/>
   <int value="1783837132" label="enable-threaded-gpu-rasterization"/>
   <int value="1803465156" label="enable-zero-suggest-most-visited"/>
+  <int value="1812368073" label="enable-new-app-list-mixer"/>
   <int value="1814671708" label="disable-password-manager-reauthentication"/>
   <int value="1817312143" label="num-raster-threads"/>
   <int value="1819256299" label="disable-webrtc-hw-decoding"/>