From ef67dec2114e6e06e28d43deb3b87f6f21dee8dc Mon Sep 17 00:00:00 2001
From: Daniel Freedman <dfreedm@google.com>
Date: Mon, 16 Nov 2015 12:09:19 -0800
Subject: [PATCH] Upgrade templates when performing the CustomElements treewalk

This calls `querySelectorAll` way less frequently while still upgrading
templates before custom elements upgrade.

`HTMLTemplateElement.decorate` will now bootstrap the template content, so
Polymer can use `decorate` when it preps the template for data binding.
---
 src/CustomElements/observe.js | 8 +-------
 src/CustomElements/upgrade.js | 6 ++++++
 src/Template/Template.js      | 9 +++++++--
 wct.conf.json                 | 5 ++++-
 4 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/CustomElements/observe.js b/src/CustomElements/observe.js
index 09e1e7e..c0c7421 100644
--- a/src/CustomElements/observe.js
+++ b/src/CustomElements/observe.js
@@ -306,18 +306,12 @@ if (originalCreateShadowRoot) {
   };
 }
 
-function upgradeAll(doc) {
-  if (HTMLTemplateElement && HTMLTemplateElement.bootstrap) {
-    HTMLTemplateElement.bootstrap(doc);
-  }
-  addedNode(doc);
-}
 // exports
 scope.watchShadow = watchShadow;
 scope.upgradeDocumentTree = upgradeDocumentTree;
 scope.upgradeDocument = upgradeDocument;
 scope.upgradeSubtree = addedSubtree;
-scope.upgradeAll = upgradeAll;
+scope.upgradeAll = addedNode;
 scope.attached = attached;
 scope.takeRecords = takeRecords;
 
diff --git a/src/CustomElements/upgrade.js b/src/CustomElements/upgrade.js
index 2d5c93a..4b1817a 100644
--- a/src/CustomElements/upgrade.js
+++ b/src/CustomElements/upgrade.js
@@ -33,6 +33,12 @@ var flags = scope.flags;
  */
 // Upgrade a node if it can be upgraded and is not already.
 function upgrade(node, isAttached) {
+  // upgrade template elements before custom elements
+  if (node.localName === 'template') {
+    if (window.HTMLTemplateElement && HTMLTemplateElement.decorate) {
+      HTMLTemplateElement.decorate(node);
+    }
+  }
   if (!node.__upgraded__ && (node.nodeType === Node.ELEMENT_NODE)) {
     var is = node.getAttribute('is');
     // find definition first by localName and secondarily by is attribute
diff --git a/src/Template/Template.js b/src/Template/Template.js
index 284b7d5..5cf73ed 100644
--- a/src/Template/Template.js
+++ b/src/Template/Template.js
@@ -28,9 +28,11 @@ if (typeof HTMLTemplateElement === 'undefined') {
       NOTE: there is no support for dynamically adding elements to templates.
     */
     HTMLTemplateElement.decorate = function(template) {
-      if (!template.content) {
-        template.content = contentDoc.createDocumentFragment();
+      // if the template is decorated, return fast
+      if (template.content) {
+        return;
       }
+      template.content = contentDoc.createDocumentFragment();
       var child;
       while (child = template.firstChild) {
         template.content.appendChild(child);
@@ -63,6 +65,9 @@ if (typeof HTMLTemplateElement === 'undefined') {
           canDecorate = false;
         }
       }
+
+      // bootstrap recursively
+      HTMLTemplateElement.bootstrap(template.content);
     };
 
     /**
diff --git a/wct.conf.json b/wct.conf.json
index 7bd506e..76d7ee0 100644
--- a/wct.conf.json
+++ b/wct.conf.json
@@ -1,3 +1,6 @@
 {
-  "suites": ["tests/runner.html"]
+  "suites": ["tests/runner.html"],
+  "clientOptions": {
+    "environmentImports": []
+  }
 }