chromeos: Remove "mash" reference in about_flags.cc

The mash flag was removed long ago, but we missed this reference to it.

Bug: none
Change-Id: I2a5c73e931152853ea2ce5fffcfebec893de9106
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2188351
Commit-Queue: James Cook <jamescook@chromium.org>
Commit-Queue: Michael Wasserman <msw@chromium.org>
Auto-Submit: James Cook <jamescook@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#766548}

chrome/browser/about_flags.cc

@@ -5540,12 +5540,6 @@ bool ShouldSkipNonDeprecatedFeatureEntry(const FeatureEntry& entry) {
 bool SkipConditionalFeatureEntry(const FeatureEntry& entry) {
   version_info::Channel channel = chrome::GetChannel();
 #if defined(OS_CHROMEOS)
-  // Don't expose mash on stable channel.
-  if (!strcmp("mash", entry.internal_name) &&
-      channel == version_info::Channel::STABLE) {
-    return true;
-  }
-
   // enable-ui-devtools is only available on for non Stable channels.
   if (!strcmp(ui_devtools::switches::kEnableUiDevTools, entry.internal_name) &&
       channel == version_info::Channel::STABLE) {