Remove old-checkbox-style flag, code and assets

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index e47a84d4eb41ee46abb62f0e8e63f30ae89d4d6b..8ba1d2ab51783674cc9971d02c41b4fac1d3b407 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -6857,18 +6857,12 @@ Keep your key file in a safe place. You will need it to create new versions of y
         </message>
       </if>
 
-      <message name="IDS_FLAGS_OLD_CHECKBOX_STYLE" desc="Name of the flag to turn off the new checkbox style.">
-        Disable new checkbox style.
-      </message>
       <message name="IDS_FLAGS_FULL_HISTORY_SYNC_NAME" desc="Name of the flag to enable full history sync.">
         Enable full history sync.
       </message>
       <message name="IDS_FLAGS_FULL_HISTORY_SYNC_DESCRIPTION" desc="Description for the flag to enable full history sync.">
         If tab sync is enabled, this feature allows you to see and delete history entries from your synced devices at chrome://history.
       </message>
-      <message name="IDS_FLAGS_OLD_CHECKBOX_STYLE_DESCRIPTION" desc="Description of the flag to turn off the new checkbox style.">
-        Disables new appearance and sizing behavior for checkboxes and radio buttons.
-      </message>
       <message name="IDS_FLAGS_DISABLE_ACCELERATED_VIDEO_DECODE_NAME" desc="Name of the flag to disable accelerated video decode where available.">
         Disable hardware-accelerated video decode.
       </message>