code/Debug/Model/Observer.php
public function onControllerFrontSendResponseAfter(Varien_Event_Observer $observer)
    {
        if (!$this->canCollect()) {
            return;
        }

        /** @var Mage_Core_Controller_Varien_Front $front */
        $front = $observer->getData('front');

        $this->updateProfiling();
        $this->getRequestInfo()->getController()->addResponseInfo($front->getResponse());
    }
public function onControllerFrontSendResponseAfter(Varien_Event_Observer $observer)
    {
        if (!$this->canCollect()) {
            return;
        }

        /** @var Mage_Core_Controller_Varien_Front $front */
        $front = $observer->getData('front');

        $this->updateProfiling();
        $this->getRequestInfo()->getController()->addResponseInfo($front->getResponse());
    }
Listens to controller_front_send_response_after. This event represents the end of a request.

@param Varien_Event_Observer $observer