Extract the element implementation logic to function mods in <webview>.

extensions/renderer/resources/guest_view/web_view/web_view.js

Index: extensions/renderer/resources/guest_view/web_view/web_view.js
diff --git a/extensions/renderer/resources/guest_view/web_view/web_view.js b/extensions/renderer/resources/guest_view/web_view/web_view.js
index fd0e45c81b01e04239d6704d51194cc3d1cfff2d..6fcf02838eb51671566fca66381034e793a3f353 100644
--- a/extensions/renderer/resources/guest_view/web_view/web_view.js
+++ b/extensions/renderer/resources/guest_view/web_view/web_view.js
@@ -137,7 +137,7 @@ WebViewImpl.prototype.onSizeChanged = function(webViewEvent) {
 
 WebViewImpl.prototype.createGuest = function() {
   this.guest.create(this.buildParams(), function() {
-    this.attachWindow();
+    this.attachWindow$();
   }.bind(this));
 };
 
@@ -178,7 +178,7 @@ WebViewImpl.prototype.buildContainerParams = function() {
   return params;
 };
 
-WebViewImpl.prototype.attachWindow = function(opt_guestInstanceId) {
+WebViewImpl.prototype.attachWindow$ = function(opt_guestInstanceId) {
   // If |opt_guestInstanceId| was provided, then a different existing guest is
   // being attached to this webview, and the current one will get destroyed.
   if (opt_guestInstanceId) {
@@ -189,7 +189,7 @@ WebViewImpl.prototype.attachWindow = function(opt_guestInstanceId) {
     this.guest = new GuestView('webview', opt_guestInstanceId);
   }
 
-  return GuestViewContainer.prototype.attachWindow.call(this);
+  return GuestViewContainer.prototype.attachWindow$.call(this);
 };
 
 // Shared implementation of executeScript() and insertCSS().