Initial implementation of new-style notification

tools/metrics/histograms/enums.xml

Index: tools/metrics/histograms/enums.xml
diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
index 94c4b4888b53967aa52466e11271813b592908b2..18eac23cdb08f63de235b7f2fcafd19599fbf0ea 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml
@@ -21512,6 +21512,7 @@ uploading your change for review.  These are checked by presubmit scripts.
   <int value="-2040471724" label="CrOSComponent:disabled"/>
   <int value="-2040115518" label="load-media-router-component-extension"/>
   <int value="-2036149591" label="FaviconsFromWebManifest:disabled"/>
+  <int value="-2035126988" label="enabled-new-style-notification"/>
   <int value="-2033225430" label="NTPMostLikelyFaviconsFromServer:disabled"/>
   <int value="-2029912304" label="StaleWhileRevalidate2:enabled"/>
   <int value="-2025367104" label="enable-material-design-ntp"/>
@@ -22165,6 +22166,7 @@ from previous Chrome versions.
   <int value="334802038" label="OfflinePreviews:disabled"/>
   <int value="346711293" label="enable-save-password-bubble"/>
   <int value="348854923" label="v8-cache-strategies-for-cache-storage"/>
+  <int value="352191859" label="disabled-new-style-notification"/>
   <int value="358399482" label="enable-high-dpi-fixed-position-compositing"/>
   <int value="358493847" label="BackgroundLoader:disabled"/>
   <int value="360391863" label="NTPOfflineBadge:enabled"/>