Bug 1655951 - Fix browser/browser_jsterm_evaluation_context_selector_pause_in_debugger.js failure. r=jdescottes.

It seems that the test was failing because the focus wasn't on the console by
the time we were trying to evaluate the input, so the Enter keypress wasn't
registered and the input not evaluated.
This is fixed by focusing the console input in `keyboardExecuteAndWaitForMessage`,
before hitting Enter.

Differential Revision: https://phabricator.services.mozilla.com/D85368

devtools/client/webconsole/test/browser/browser_jsterm_evaluation_context_selector_pause_in_debugger.js

@@ -61,6 +61,10 @@ add_task(async function() {
   );
   ok(true, "Evaluation result is the expected one");
 
+  // Cleanup
+  await clearOutput(hud);
+  setInputValue(hud, "");
+
   info("Resume the debugger");
   await resume(dbg);
 

devtools/client/webconsole/test/browser/head.js

@@ -307,6 +307,7 @@ function keyboardExecuteAndWaitForMessage(
   matchingText,
   selector = ".message"
 ) {
+  hud.jsterm.focus();
   setInputValue(hud, input);
   const onMessage = waitForMessage(hud, matchingText, selector);
   if (isEditorModeEnabled(hud)) {