MD Downloads: reduce the amount of dom-ifs to speed Polymer up

chrome/browser/resources/md_downloads/item.html

Index: chrome/browser/resources/md_downloads/item.html
diff --git a/chrome/browser/resources/md_downloads/item.html b/chrome/browser/resources/md_downloads/item.html
index 21ef72d157a25d435047ab2fe419551397a60ecb..109de2921bdb47c6337038fa0ee7369fc5716137 100644
--- a/chrome/browser/resources/md_downloads/item.html
+++ b/chrome/browser/resources/md_downloads/item.html
@@ -11,9 +11,7 @@
 
 <dom-module id="downloads-item">
   <template>
-    <template is="dom-if" if="[[!hideDate]]">
-      <h3 id="date">[[computeDate_(data_.since_string, data_.date_string)]]</h3>
-    </template>
+    <h3 id="date" hidden$="[[hideDate]]">[[computeDate_(data_.since_string, data_.date_string)]]</h3>
 
     <paper-material id="content" on-dragstart="onDragStart_"
         elevation$="[[computeElevation_(isActive_)]]"
@@ -39,29 +37,21 @@
 
         <div id="description">[[computeDescription_(data_.state, data_.danger_type, data_.file_name, data_.progress_status_text)]]</div>
 
-        <template is="dom-if" if="[[showProgress_]]">
-          <paper-progress id="progress"
-              indeterminate$="[[isIndeterminate_(data_.percent)]]"
-              value$="[[data_.percent]]"></paper-progress>
-        </template>
+        <paper-progress id="progress" hidden$="[[!showProgress_]]"
+            indeterminate$="[[isIndeterminate_(data_.percent)]]"
+            value$="[[data_.percent]]"></paper-progress>
 
         <div id="safe" class="controls" hidden$="[[isDangerous_]]">
           <a is="action-link" id="show" i18n-content="controlShowInFolder"
               on-click="onShowClick_" hidden$="[[!completelyOnDisk_]]"></a>
-          <template is="dom-if" if="[[data_.retry]]">
-            <paper-button id="retry"
+          <template is="dom-if" if="[[!completelyOnDisk_]]">
+            <paper-button id="retry" hidden$="[[!data_.retry]]"
                 on-click="onRetryClick_">[[i18n_.retry]]</paper-button>
-          </template>
-          <template is="dom-if" if="[[isInProgress_]]">
-            <paper-button id="pause"
+            <paper-button id="pause" hidden$="[[!isInProgress_]]"
                 on-click="onPauseClick_">[[i18n_.pause]]</paper-button>
-          </template>
-          <template is="dom-if" if="[[data_.resume]]">
-            <paper-button id="resume"
+            <paper-button id="resume" hidden$="[[!data_.resume]]"
                 on-click="onResumeClick_">[[i18n_.resume]]</paper-button>
-          </template>
-          <template is="dom-if" if="[[showCancel_]]">
-            <paper-button id="cancel"
+            <paper-button id="cancel" hidden$="[[!showCancel_]]"
                 on-click="onCancelClick_">[[i18n_.cancel]]</paper-button>
           </template>
           <span id="controlled-by"><!-- Text populated dynamically. --></span>
@@ -70,20 +60,16 @@
         <template is="dom-if" if="[[isDangerous_]]">
           <div id="dangerous" class="controls">
             <!-- Dangerous file types (e.g. .exe, .jar). -->
-            <template is="dom-if" if="[[!isMalware_]]">
-              <paper-button id="discard" on-click="onDiscardDangerous_"
-                  class="discard">[[i18n_.discard]]</paper-button>
-              <paper-button id="save" on-click="onSaveDangerous_"
-                  class="keep">[[i18n_.save]]</paper-button>
-            </template>
+            <paper-button id="discard" on-click="onDiscardDangerous_"
+                class="discard" hidden$="[[isMalware_]]">[[i18n_.discard]]</paper-button>
+            <paper-button id="save" on-click="onSaveDangerous_"
+                class="keep" hidden$="[[isMalware_]]">[[i18n_.save]]</paper-button>
 
             <!-- Things that safe browsing has determined to be dangerous. -->
-            <template is="dom-if" if="[[isMalware_]]">
-              <paper-button id="danger-remove" on-click="onDiscardDangerous_"
-                  class="discard">[[i18n_.remove]]</paper-button>
-              <paper-button id="restore" on-click="onSaveDangerous_"
-                  class="keep">[[i18n_.restore]</paper-button>
-            </template>
+            <paper-button id="danger-remove" on-click="onDiscardDangerous_"
+                class="discard" hidden$="[[!isMalware_]]">[[i18n_.remove]]</paper-button>
+            <paper-button id="restore" on-click="onSaveDangerous_"
+                class="keep" hidden$="[[!isMalware_]]">[[i18n_.restore]</paper-button>
           </div>
         </template>
       </div>