Bug 1561092 - Fix intermittent browser_dbg-wasm-sourcemaps test. r=davidwalsh

Differential Revision: https://phabricator.services.mozilla.com/D36837

--HG--
extra : moz-landing-system : lando

devtools/client/debugger/src/actions/ast/setInScopeLines.js

@@ -6,6 +6,7 @@
 
 import {
   hasInScopeLines,
+  hasSourceActor,
   getSourceWithContent,
   getVisibleSelectedFrame,
 } from "../../selectors";
@@ -66,7 +67,11 @@ export function setInScopeLines(cx: Context) {
     }
 
     const { location } = visibleFrame;
-    if (hasInScopeLines(getState(), location)) {
+
+    if (
+      hasInScopeLines(getState(), location) ||
+      !hasSourceActor(getState(), location.sourceId)
+    ) {
       return;
     }