<webview>: Fixed out-of-date comment + Only copy attributes to BrowserPlugin if they exist.

chrome/renderer/resources/extensions/web_view.js

Index: chrome/renderer/resources/extensions/web_view.js
diff --git a/chrome/renderer/resources/extensions/web_view.js b/chrome/renderer/resources/extensions/web_view.js
index 7187089b371c112eed89b24a005f09f7e79c979c..d6143d1d2a08d0687abaea2ef5863a182bd752d2 100644
--- a/chrome/renderer/resources/extensions/web_view.js
+++ b/chrome/renderer/resources/extensions/web_view.js
@@ -48,12 +48,16 @@ function WebView(node) {
 
   this.objectNode_ = document.createElement('object');
   this.objectNode_.type = 'application/browser-plugin';
-  // The <object> node fills in the <browser> container.
+  // The <object> node fills in the <webview> container.
   this.objectNode_.style.width = '100%';
   this.objectNode_.style.height = '100%';
   WEB_VIEW_ATTRIBUTES.forEach(function(attributeName) {
-    this.objectNode_.setAttribute(
-        attributeName, this.node_.getAttribute(attributeName));
+    // Only copy attributes that have been assigned values, rather than copying
+    // a series of undefined attributes to BrowserPlugin.
+    if (this.node_.hasAttribute(attributeName)) {
+      this.objectNode_.setAttribute(
+          attributeName, this.node_.getAttribute(attributeName));
+    }
   }, this);
 
   shadowRoot.appendChild(this.objectNode_);