Fix chrome.runtime.sendMessage background page memory leak.

chrome/renderer/resources/extensions/messaging.js

Index: chrome/renderer/resources/extensions/messaging.js
diff --git a/chrome/renderer/resources/extensions/messaging.js b/chrome/renderer/resources/extensions/messaging.js
index a9a39512e99b61c43e48d8513e32a085503aa5f8..a39ecb1cb6c6b7f7c13ac907fc58397cfc3fd445 100644
--- a/chrome/renderer/resources/extensions/messaging.js
+++ b/chrome/renderer/resources/extensions/messaging.js
@@ -161,7 +161,8 @@
     if (!requestEvent.hasListeners())
       return false;
     var port = createPort(portId, channelName);
-    port.onMessage.addListener(function(request) {
+
+    function messageListener(request) {
       var responseCallbackPreserved = false;
       var responseCallback = function(response) {
         if (port) {
@@ -198,7 +199,13 @@
           port = null;
         }
       }
-    });
+    }
+
+    port.onDestroy_ = function() {
+      port.onMessage.removeListener(messageListener);
+    };
+    port.onMessage.addListener(messageListener);
+
     var eventName = (isSendMessage ?
           (isExternal ?
               "runtime.onMessageExternal" : "runtime.onMessage") :