Fixed a possible memory leak and support null pointers in AutomationEventObservers' NotifyEvent.

chrome/browser/automation/automation_event_observers.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <string>
 
 #include "base/logging.h"
 #include "base/stringprintf.h"
 #include "chrome/browser/automation/automation_event_observers.h"
 #include "chrome/browser/automation/automation_event_queue.h"
@@ skipping 10 matching lines @@
     : event_queue_(event_queue),
       recurring_(recurring),
       observer_id_(-1),
       event_count_(0) {
   DCHECK(event_queue_ != NULL);
 }
 
 AutomationEventObserver::~AutomationEventObserver() {}
 
 void AutomationEventObserver::NotifyEvent(DictionaryValue* value) {
   if (event_queue_) {

[dennis_jeffrey, 2012/05/16 16:55:42]

Will "value" get deleted on the "true" branch of this condition?

[craigdh, 2012/05/16 17:00:55]

Yes. On "true" the AutomationEventQueue takes ownership.

+    if (!value)
+      value = new DictionaryValue;

[dennis_jeffrey, 2012/05/16 16:55:42]

Is this check needed?  It looks like both callers affected by this CL always
create a new DictionaryValue before invoking this function.  What about issuing
an error if the value isn't set by the caller?

[craigdh, 2012/05/16 17:00:55]

Right now NULL is not being passed, but is because both current uses have
additional information to return. In general that seemed like an unnecessary
limitation and now the usage will be more similar to SendSuccess().

+    value->SetInteger("observer_id", GetId());
     event_queue_->NotifyEvent(
         new AutomationEventQueue::AutomationEvent(
             GetId(), value));
     event_count_++;
+  } else if (value) {
+    delete value;
   }
 }
 
 void AutomationEventObserver::Init(int observer_id) {
     observer_id_ = observer_id;
 }
 
 int AutomationEventObserver::GetId() const {
   return observer_id_;
 }
@@ skipping 39 matching lines @@
   if (type == content::NOTIFICATION_DOM_OPERATION_RESPONSE) {
     content::Details<content::DomOperationNotificationDetails> dom_op_details(
         details);
     if ((dom_op_details->automation_id == automation_id_ ||
          automation_id_ == -1) &&
         (event_name_.length() == 0 ||
          event_name_.compare(dom_op_details->json) == 0)) {
       DictionaryValue* dict = new DictionaryValue;
       dict->SetString("type", "raised_event");
       dict->SetString("name", dom_op_details->json);
-      dict->SetInteger("observer_id", GetId());
       NotifyEvent(dict);
     }
   }
   // Nothing should happen after RemoveIfDone() as it may delete the object.
   RemoveIfDone();
 }