Replace --add-to-shelf flag with kAppBanners feature.

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 064b0c25fd0fcb18f09bdc3368e567d1d5c9ee87..5531187e68fc3ac22dedbf2c8a15e90b99479afa 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml
@@ -22298,7 +22298,6 @@ from previous Chrome versions.
   <int value="-1028733699" label="MacViewsWebUIDialogs:disabled"/>
   <int value="-1022971520" label="enable-search-button-in-omnibox-for-str"/>
   <int value="-1020450980" label="gesture-deletion"/>
-  <int value="-1016202433" label="disable-add-to-shelf"/>

[Matt Giuca, 2017/06/22 01:40:38]

Don't delete enums.

Add " (deprecated)" to the end of the name (seems to be the convention).

[benwells, 2017/06/22 05:57:48]

Done.

   <int value="-1015006759" label="ImportantSitesInCBD:disabled"/>
   <int value="-998255750" label="ExperimentalKeyboardLockUI:enabled"/>
   <int value="-996673716" label="enable-web-app-frame"/>
@@ -22486,6 +22485,7 @@ from previous Chrome versions.
   <int value="-340023285" label="WebNFC:enabled"/>
   <int value="-329727402" label="disable-files-quick-view"/>
   <int value="-328361990" label="enable-experimental-extension-apis"/>
+  <int value="-326083626" label="AppBanners:disabled"/>
   <int value="-323831744" label="token-binding:enabled"/>
   <int value="-322937746" label="disable-desktop-capture-picker-new-ui"/>
   <int value="-322827131" label="tab-management-experiment-type-basil"/>
@@ -22665,7 +22665,6 @@ from previous Chrome versions.
   <int value="371268743" label="OmniboxUIExperimentVerticalMargin:disabled"/>
   <int value="372460068" label="QuickUnlockFingerprint:disabled"/>
   <int value="377093001" label="WebRtcHWH264Encoding:disabled"/>
-  <int value="379326303" label="enable-add-to-shelf"/>
   <int value="379428799" label="security-chip-animation"/>
   <int value="385969127" label="disable-win32k-lockdown"/>
   <int value="387178525" label="VideoFullscreenOrientationLock:enabled"/>
@@ -22830,6 +22829,7 @@ from previous Chrome versions.
   <int value="943319566" label="enable-intent-picker"/>
   <int value="952558794" label="enable-remote-assistance"/>
   <int value="980396200" label="enable-new-korean-ime"/>
+  <int value="981818901" label="AppBanners:enabled"/>
   <int value="982032277" label="NTPOfflineBadge:disabled"/>
   <int value="982511393" label="NTPArticleSuggestions:disabled"/>
   <int value="983311394" label="tab-management-experiment-type"/>