Revert "Trigger exception debug event for promises at the throw site."

test/mjsunit/es6/debug-promises-caught-all.js

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --harmony-promises --expose-debug-as debug
 
 // Test debug events when we listen to all exceptions and
 // there is a catch handler for the exception thrown in a Promise.
-// We expect a normal Exception debug event to be triggered.
+// Expectation:
+//  - only the normal Exception debug event is triggered.
 
 Debug = debug.Debug;
 
 var log = [];
 var step = 0;
 
 var p = new Promise(function(resolve, reject) {
   log.push("resolve");
   resolve();
 });
 
 var q = p.chain(
   function() {
     log.push("throw");
     throw new Error("caught");
   });
 
 q.catch(
   function(e) {
     assertEquals("caught", e.message);
   });
 
 function listener(event, exec_state, event_data, data) {
   try {
     // Ignore exceptions during startup in stress runs.
     if (step >= 1) return;
     assertEquals(["resolve", "end main", "throw"], log);
+    assertTrue(event != Debug.DebugEvent.PendingExceptionInPromise);
     if (event == Debug.DebugEvent.Exception) {
       assertEquals("caught", event_data.exception().message);
       assertEquals(undefined, event_data.promise());
-      assertFalse(event_data.uncaught());
       step++;
     }
   } catch (e) {
     // Signal a failure with exit code 1.  This is necessary since the
     // debugger swallows exceptions and we expect the chained function
     // and this listener to be executed after the main script is finished.
     print("Unexpected exception: " + e + "\n" + e.stack);
     quit(1);
   }
 }
 
 Debug.setBreakOnException();
 Debug.setListener(listener);
 
 log.push("end main");