DevTools: create test infrastructure so devtools drives the test

third_party/WebKit/LayoutTests/http/tests/inspector-unit/text-prompt.js

 TestRunner.addResult("This tests if the TextPrompt autocomplete works properly.");
 
 var suggestions = ["heyoo", "hey it's a suggestion", "hey another suggestion"].map(s => ({text: s}));
 var prompt = new UI.TextPrompt();
 prompt.initialize(() => Promise.resolve(suggestions));
 var div = document.createElement("div");
 UI.inspectorView.element.appendChild(div);
 prompt.attachAndStartEditing(div);
 prompt.setText("hey");
-TestRunner.addSniffer(prompt, "_completionsReady").then(step2);
+TestRunner.addSnifferPromise(prompt, "_completionsReady").then(step2);
 prompt.complete();
 function step2() {
     TestRunner.addResult("Text:" + prompt.text());
     TestRunner.addResult("TextWithCurrentSuggestion:" + prompt.textWithCurrentSuggestion());
 
     TestRunner.addResult("Test with inexact match:");
     prompt.clearAutocomplete();
     prompt.setText("inexactmatch");
-    TestRunner.addSniffer(prompt, "_completionsReady").then(step3);
+    TestRunner.addSnifferPromise(prompt, "_completionsReady").then(step3);
     prompt.complete();
 }
 function step3() {
     TestRunner.addResult("Text:" + prompt.text());
     TestRunner.addResult("TextWithCurrentSuggestion:" + prompt.textWithCurrentSuggestion());
     TestRunner.completeTest();
 }