Adding flags and finch trial for the removal of All Bookmarks view.

ios/chrome/browser/about_flags.mm

Index: ios/chrome/browser/about_flags.mm
diff --git a/ios/chrome/browser/about_flags.mm b/ios/chrome/browser/about_flags.mm
index cdf1bf7b312aefffbe2e65823c4a03229820f3c3..96dbc647d1973dfc9435e50ff2e76ca010332edc 100644
--- a/ios/chrome/browser/about_flags.mm
+++ b/ios/chrome/browser/about_flags.mm
@@ -100,6 +100,15 @@ void AppendSwitchesFromExperimentalSettings(base::CommandLine* command_line) {
     command_line->AppendSwitch(switches::kDisableLRUSnapshotCache);
   }
 
+  // Populate command line flag for the AllBookmarks from the
+  // configuration plist.
+  NSString* enableAllBookmarks = [defaults stringForKey:@"AllBookmarks"];
+  if ([enableAllBookmarks isEqualToString:@"Enabled"]) {
+    command_line->AppendSwitch(switches::kEnableAllBookmarksView);
+  } else if ([enableAllBookmarks isEqualToString:@"Disabled"]) {
+    command_line->AppendSwitch(switches::kDisableAllBookmarksView);
+  }
+
   // Populate command line flag for the NTP favicons experiment from the
   // configuration plist.
   NSString* enableNTPFavicons = [defaults stringForKey:@"EnableNTPFavicons"];