Re-enable display zoom setting by default

This patch enables display zoom setting by default on chromeos.

TBR=oshima@chromium.org

Bug: 835030
Change-Id: I48c2cfeed6b74bced55d3274414adfd2bdc283e9
Reviewed-on: https://chromium-review.googlesource.com/1025550Reviewed-by: Malay Keshav <malaykeshav@chromium.org>
Commit-Queue: Malay Keshav <malaykeshav@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553018}

ui/display/display_switches.cc

@@ -76,7 +76,13 @@ const base::Feature kUseMonitorColorSpace{"UseMonitorColorSpace",
 // TODO(malaykeshav): Remove this in M68 when the feature has been in stable for
 // atleast one milestone.
 constexpr base::Feature kEnableDisplayZoomSetting{
-    "EnableDisplayZoomSetting", base::FEATURE_DISABLED_BY_DEFAULT};
+  "EnableDisplayZoomSetting",
+#if defined(OS_CHROMEOS)
+      base::FEATURE_ENABLED_BY_DEFAULT
+#else
+      base::FEATURE_DISABLED_BY_DEFAULT
+#endif
+};
 
 bool IsDisplayZoomSettingEnabled() {
   return base::FeatureList::IsEnabled(kEnableDisplayZoomSetting);