Fixup console pretty print test (#5689)

* Fixup console pretty print test

* Make selectSource more paranoid

Author: jasonLaster

src/test/mochitest/browser_dbg-preview-module.js

@@ -10,7 +10,7 @@ add_task(async function() {
   navigate(dbg, "doc-on-load.html");
 
   // wait for `top-level.js` to load and to pause at a debugger statement
-  await waitForSelectedSource(dbg);
+  await waitForSelectedSource(dbg, "top-level.js");
   await waitForPaused(dbg);
 
   const popupPreviewed = waitForDispatch(dbg, "SET_PREVIEW");

src/test/mochitest/browser_dbg-reload.js

@@ -19,6 +19,7 @@ async function waitForBreakpoint(dbg, location) {
 
 add_task(async function() {
   const dbg = await initDebugger("reload/doc-reload.html");
+
   await waitForSource(dbg, "sjs_code_reload");
   await selectSource(dbg, "sjs_code_reload");
   await addBreakpoint(dbg, "sjs_code_reload", 2);