Bug 1536860 - Telemetry for deprecated Array generics. r=jorendorff datareview=chutten

Differential Revision: https://phabricator.services.mozilla.com/D24208

js/src/jsfriendapi.h

@@ -170,6 +170,7 @@ enum {
   JS_TELEMETRY_GC_MARK_RATE,
   JS_TELEMETRY_PRIVILEGED_PARSER_COMPILE_LAZY_AFTER_MS,
   JS_TELEMETRY_WEB_PARSER_COMPILE_LAZY_AFTER_MS,
+  JS_TELEMETRY_DEPRECATED_ARRAY_GENERICS,
   JS_TELEMETRY_END
 };
 

js/src/vm/SelfHosting.cpp

@@ -2088,6 +2088,10 @@ static bool intrinsic_WarnDeprecatedMethod(JSContext* cx, unsigned argc,
       return false;
     }
 
+    if (!cx->realm()->isProbablySystemCode()) {
+      cx->runtime()->addTelemetry(JS_TELEMETRY_DEPRECATED_ARRAY_GENERICS, id);
+    }
+
     cx->realm()->warnedAboutArrayGenericsMethods |= mask;
   }
 

js/xpconnect/src/XPCJSRuntime.cpp

@@ -2750,6 +2750,9 @@ static void AccumulateTelemetryCallback(int id, uint32_t sample,
     case JS_TELEMETRY_GC_MARK_RATE:
       Telemetry::Accumulate(Telemetry::GC_MARK_RATE, sample);
       break;
+    case JS_TELEMETRY_DEPRECATED_ARRAY_GENERICS:
+      Telemetry::Accumulate(Telemetry::JS_DEPRECATED_ARRAY_GENERICS, sample);
+      break;
     default:
       MOZ_ASSERT_UNREACHABLE("Unexpected JS_TELEMETRY id");
   }

toolkit/components/telemetry/Histograms.json

@@ -1033,6 +1033,15 @@
     "n_buckets": 10,
     "description": "Time elapsed between the moment a function is lazy-parsed (end of parsing of the ScriptSource) and the moment it is recompiled as non-lazy (start of compilation), in milliseconds, for web code."
   },
+  "JS_DEPRECATED_ARRAY_GENERICS": {
+    "record_in_processes": ["content"],
+    "alert_emails": ["jdemooij@mozilla.com"],
+    "expires_in_version": "74",
+    "bug_numbers": [1536860],
+    "kind": "enumerated",
+    "n_values": 20,
+    "description": "A array generic function was called, like Array.forEach etc. See ARRAY_GENERICS_* defines in SelfHostingDefines.h for the meaning of values."
+  },
   "XUL_CACHE_DISABLED": {
     "record_in_processes": ["main", "content"],
     "expires_in_version": "default",