DevTools: Fix flaky debugger-uncaught-promise-on-dom-exception.html

BUG=425196
TBR=lushnikov

Review URL: https://codereview.chromium.org/665983002

git-svn-id: svn://svn.chromium.org/blink/trunk@184014 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/inspector/sources/debugger/debugger-uncaught-promise-on-dom-exception.html

@@ -45,12 +45,12 @@ function test()
 
     function step1()
     {
-        InspectorTest.addConsoleViewSniffer(addMessage, true);
         InspectorTest.runTestFunctionAndWaitUntilPaused(didPause);
     }
 
     function didPause(callFrames, reason, breakpointIds, asyncStackTrace)
     {
+        InspectorTest.addConsoleViewSniffer(addMessage, true);
         InspectorTest.evaluateInPage("runPromisesFromInspector()", resumeExecution);
     }