MD Settings: Display: Move event listeners to dialog open/close

chrome/browser/resources/settings/device_page/display_overscan_dialog.js

Index: chrome/browser/resources/settings/device_page/display_overscan_dialog.js
diff --git a/chrome/browser/resources/settings/device_page/display_overscan_dialog.js b/chrome/browser/resources/settings/device_page/display_overscan_dialog.js
index 4cb019fcabdedb1d74e988030345aaf1032ed325..885ad80a5b861e7ad5e0653352b42d67f5e67031 100644
--- a/chrome/browser/resources/settings/device_page/display_overscan_dialog.js
+++ b/chrome/browser/resources/settings/device_page/display_overscan_dialog.js
@@ -30,23 +30,16 @@ Polymer({
    */
   keyHandler_: null,
 
-  /** @override */
-  attached: function() {
+  open: function() {
     this.keyHandler_ = this.handleKeyEvent_.bind(this);
     window.addEventListener('keydown', this.keyHandler_);

[Dan Beam, 2016/09/27 00:04:52]

why are we using window.addEventListener() rather than a more narrow scope like
this.addEventListener()?

[stevenjb, 2016/09/28 17:49:35]

Because I'm still fairly new to web development and forgot that you can do that?

Changed.

-  },
-
-  /** @override */
-  detached: function() {
-    window.removeEventListener('keydown', this.keyHandler_);
-  },
-
-  open: function() {
     this.comitted_ = false;
     this.$.dialog.showModal();
   },
 
   close: function() {
+    window.removeEventListener('keydown', this.keyHandler_);
+
     this.displayId = '';  // Will trigger displayIdChanged_.
 
     if (this.$.dialog.open)