From 36e9310f67fdf2b9d92a1ac21e20698e14f95c97 Mon Sep 17 00:00:00 2001
From: Daniel Freedman <dfreedm@google.com>
Date: Thu, 21 Sep 2017 10:22:24 -0700
Subject: [PATCH] Just move the style, don't clone

Similar to 61b2c8a54412fa6e040b8c12e0d8ea402331e4a4
---
 src/lib/custom-style.html | 45 ++++++++++++---------------------------
 1 file changed, 14 insertions(+), 31 deletions(-)

diff --git a/src/lib/custom-style.html b/src/lib/custom-style.html
index 031f83b327..0d750eac18 100644
--- a/src/lib/custom-style.html
+++ b/src/lib/custom-style.html
@@ -123,6 +123,19 @@
       if (this.__appliedElement !== this) {
         this.__appliedElement.__cssBuild = this.__cssBuild;
       }
+      /*
+      HTML Imports styling the main document are deprecated in Chrome
+      https://crbug.com/523952
+
+      If this element is not in the main document, then it must be in an HTML Import document.
+      In that case, move the custom style to the main document.
+
+      The ordering of `<custom-style>` should stay the same as when loaded by HTML Imports, but there may be odd
+      cases of ordering w.r.t the main document styles.
+      */
+      if (this.ownerDocument !== window.document && this.__appliedElement === this) {
+        document.head.appendChild(this);
+      }
       // needed becuase elements in imports do not get 'attached'
       // TODO(sorvell): we could only do this if and only if
       // this.ownerDocument != document;
@@ -139,33 +152,6 @@
     },
 
     _tryApply: function() {
-      var createdAppliedElement = false;
-      /*
-      HTML Imports styling the main document are deprecated in Chrome
-      https://crbug.com/523952
-
-      If this element is not in the main document, then it must be in an HTML Import document.
-      In that case, copy the style into the main document and disable the current style.
-      `__appliedElement` is used by the HTML Imports polyfill for this use case, and already understood by
-      ShadyCSS's Custom Style Interface.
-
-      The ordering of `<custom-style>` should stay the same as when loaded by HTML Imports, but there may be odd
-      cases of ordering w.r.t the main document styles.
-      */
-      if (this.ownerDocument !== window.document && this.__appliedElement === this) {
-        // Can't just cloneNode this style because it will infinite loop
-        var appliedElement = document.createElement('style');
-        appliedElement.textContent = this.textContent;
-        // copy css build type
-        appliedElement.__cssBuild = this.__cssBuild;
-        // set a back pointer to this custom style for use inside of styleDefaults
-        appliedElement.__importElement = this;
-        // disable this style
-        this.setAttribute('media', 'none');
-        this.__appliedElement = appliedElement;
-        document.head.appendChild(appliedElement);
-        createdAppliedElement = true;
-      }
       if (!this._appliesToDocument) {
         // only apply variables if and only if this style is not inside
         // a dom-module
@@ -190,12 +176,9 @@
             var self = this;
             var observer = new MutationObserver(function() {
               observer.disconnect();
-              if (createdAppliedElement) {
-                self.__appliedElement.textContent = self.textContent;
-              }
               self._apply(true);
             });
-            observer.observe(createdAppliedElement ? this : e, {childList: true});
+            observer.observe(e, {childList: true});
           }
         }
       }