Enabled enhanced bookmarks flag for all users.

Enhanced bookmarks flag option was used to be shown only if user enrolled into experiment. Enabling it for all users because if user has multiple profiles there is no currently a way to enable this option properly.
Long term fix would be to make about_flags aware of user preferences.
For now showing to all users looks like a "lesser evil" then not giving an option to opt-out of experiment.

BUG=

Review URL: https://codereview.chromium.org/686393003

Cr-Commit-Position: refs/heads/master@{#302273}

chrome/browser/about_flags.cc

@@ -2126,22 +2126,6 @@ void GetSanitizedEnabledFlags(
 
 bool SkipConditionalExperiment(const Experiment& experiment,
                                FlagsStorage* flags_storage) {
-  if (experiment.internal_name ==
-      std::string("enhanced-bookmarks-experiment")) {
-#if defined(OS_ANDROID)
-      // On Android, user can opt in.
-      return false;
-#else
-    CommandLine* command_line = CommandLine::ForCurrentProcess();
-    // Dont't skip experiment if it has non default value.
-    // It means user selected it.
-    if (command_line->HasSwitch(switches::kEnhancedBookmarksExperiment))
-      return false;
-
-    return !IsEnhancedBookmarksExperimentEnabled(flags_storage);
-#endif
-  }
-
   if ((experiment.internal_name == std::string("manual-enhanced-bookmarks")) ||
       (experiment.internal_name ==
            std::string("manual-enhanced-bookmarks-optout"))) {