Deregister notification listeners when packing is done.

Deregistering the handlers avoids them being called once the packing
operation is done, and an unrelated future pack operation is in
progress. It also frees up a bit of memory.

BUG=791895

Change-Id: I52b8382d18b95637c868c1cdb91fed4b0f6fd276
Reviewed-on: https://chromium-review.googlesource.com/c/1317208Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Anand Mistry <amistry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605540}

chrome/browser/resources/chromeos/zip_archiver/js/app.js

@@ -624,6 +624,28 @@ unpacker.app = {
                 function() {});
           }, unpacker.app.PACKING_NOTIFICATION_DELAY);
 
+          var progressNotificationCreated = false;
+          // If notification is closed while packing is in progress, flag to
+          // create/update is reset.
+          var onNotificationClosed = function(notificationId) {
+            if (notificationId === compressorId.toString())
+              progressNotificationCreated = false;
+          };
+          var onNotificationButtonClicked = function(
+              notificationId, buttonIndex) {
+            if (notificationId === compressorId.toString())
+              compressor.sendCancelArchiveRequest();
+          };
+          chrome.notifications.onClosed.addListener(onNotificationClosed);
+          chrome.notifications.onButtonClicked.addListener(
+              onNotificationButtonClicked);
+          var clearNotifications = function(compressorId) {
+            chrome.notifications.clear(compressorId.toString(), function() {});
+            chrome.notifications.onClosed.removeListener(onNotificationClosed);
+            chrome.notifications.onButtonClicked.removeListener(
+                onNotificationButtonClicked);
+          };
+
           var onError = function(compressorId) {
             clearTimeout(deferredNotificationTimer);
             chrome.notifications.create(
@@ -649,8 +671,7 @@ unpacker.app = {
             // content of a zip file is small it will flash the notification.
             // Thus we clear the notification with a delay to avoid flashing.
             setTimeout(function() {
-              chrome.notifications.clear(
-                  compressorId.toString(), function() {});
+              clearNotifications(compressorId);
             }, unpacker.app.PACKING_NOTIFICATION_CLEAR_DELAY);
             unpacker.app.cleanupCompressor(
                 compressorId, false /* hasError */, false /* canceled */);
@@ -658,12 +679,11 @@ unpacker.app = {
 
           var onCancel = function(compressorId) {
             clearTimeout(deferredNotificationTimer);
-            chrome.notifications.clear(compressorId.toString(), function() {});
+            clearNotifications(compressorId);
             unpacker.app.cleanupCompressor(
                 compressorId, false /* hasError */, true /* canceled */);
           };
 
-          var progressNotificationCreated = false;
           var progressValue = -1;
           var onProgress = function(compressorId, progress) {
             clearTimeout(deferredNotificationTimer);
@@ -703,17 +723,6 @@ unpacker.app = {
           };
 
           compressor.compress(onSuccess, onError, onProgress, onCancel);
-
-          // If notification is closed while packing is in progress, flag to
-          // create/update is reset.
-          chrome.notifications.onClosed.addListener(function() {
-            progressNotificationCreated = false;
-          });
-          chrome.notifications.onButtonClicked.addListener(function(
-              notificationId, buttonIndex) {
-            if (notificationId === compressorId.toString())
-              compressor.sendCancelArchiveRequest();
-          });
         });
   },