Bug 1870277 - Include failure message when a feature is marked as fai…

…led. r=aosmond

This will help us figure out why things are failing in telemetry

Differential Revision: https://phabricator.services.mozilla.com/D196576

UltraBlame original commit: 8fd04cb03fbd84435d9834d1de340c2f64e013bb

gfx/config/gfxFeature.cpp

@@ -1411,6 +1411,34 @@ get
 ;
 break
 ;
+case
+FeatureStatus
+:
+:
+Failed
+:
+status
+.
+AppendPrintf
+(
+"
+%
+s
+:
+%
+s
+"
+FeatureStatusToString
+(
+value
+)
+GetFailureMessage
+(
+)
+)
+;
+break
+;
 default
 :
 status