Only allow overly scrollbars experiement on ChromeOS.

It'll be a while before Aura (Win/Linux) are ready for this.

BUG=274010
[email protected]

Review URL: https://codereview.chromium.org/24281008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225015 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index b627aa5..2daade6 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -725,7 +725,7 @@
     IDS_FLAGS_ENABLE_OVERLAY_SCROLLBARS_DESCRIPTION,
     // Uses the system preference on Mac (a different implementation).
     // On Android, this is always enabled.
-    kOsWin | kOsLinux | kOsCrOS,
+    kOsCrOS,
     SINGLE_VALUE_TYPE(switches::kEnableOverlayScrollbars)
   },
   {