Replace i18n-values with $i18n{} mechanism in chrome://slow debug page.

Also minor cleanups:
 - Remove invalid width=100% HTML attribute
 - Remove unnecessary CSS classes.
 - Remove unnecessary <script> dependencies
 - Remove unnecessary usage of Grit's flattenhtml="true"
 - Add compress="gzip" for chrome://slow resources.

Bug: 677338
Change-Id: I1879e414e845809e2d778a23961e379c9a2b74a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1526814
Auto-Submit: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641737}
diff --git a/chrome/browser/browser_resources.grd b/chrome/browser/browser_resources.grd
index 726befb2..af3abeb 100644
--- a/chrome/browser/browser_resources.grd
+++ b/chrome/browser/browser_resources.grd
@@ -550,11 +550,10 @@
           </else>
         </if>
         <include name="IDR_CERT_MANAGER_DIALOG_HTML" file="resources\chromeos\certificate_manager_dialog.html" flattenhtml="true" type="BINDATA" />
-        <include name="IDR_SLOW_HTML" file="resources\chromeos\slow.html" flattenhtml="true" type="BINDATA" />
-        <include name="IDR_SLOW_JS" file="resources\chromeos\slow.js" type="BINDATA" />
+        <include name="IDR_SLOW_CSS" file="resources\chromeos\slow.css" type="BINDATA" compress="gzip" />
+        <include name="IDR_SLOW_HTML" file="resources\chromeos\slow.html" type="BINDATA" compress="gzip" />
+        <include name="IDR_SLOW_JS" file="resources\chromeos\slow.js" type="BINDATA" compress="gzip" />
         <include name="IDR_HATS_HTML" file="resources\chromeos\hats\hats.html" flattenhtml="false" type="BINDATA" />
-      </if>
-      <if expr="chromeos">
         <include name="IDR_DEMO_APP_MANIFEST" file="resources\chromeos\demo_app\manifest.json" type="BINDATA" />
         <include name="IDR_WALLPAPERMANAGER_MANIFEST" file="resources\chromeos\wallpaper_manager\manifest.json" type="BINDATA" />
         <include name="IDR_FIRST_RUN_DIALOG_MANIFEST" file="resources\chromeos\first_run\app/manifest.json" type="BINDATA" />
diff --git a/chrome/browser/resources/chromeos/slow.html b/chrome/browser/resources/chromeos/slow.html
index d3736c9e..5392c89 100644
--- a/chrome/browser/resources/chromeos/slow.html
+++ b/chrome/browser/resources/chromeos/slow.html
@@ -1,5 +1,5 @@
 <!doctype html>
-<html i18n-values="dir:textdirection;lang:language">
+<html dir="$i18n{textdirection}" lang="$i18n{language}">
 <head>
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1.0,
@@ -7,23 +7,19 @@
 <link rel="stylesheet" href="chrome://resources/css/text_defaults.css">
 <link rel="stylesheet" href="chrome://resources/css/widgets.css">
 <link rel="stylesheet" href="slow.css">
-<script src="chrome://resources/js/load_time_data.js"></script>
 <script src="chrome://resources/js/cr.js"></script>
-<script src="chrome://resources/js/cr/event_target.js"></script>
 <script src="chrome://resources/js/util.js"></script>
-<script src="chrome://slow/slow.js"></script>
-<script src="chrome://slow/strings.js"></script>
+<script src="slow.js"></script>
 </head>
 <body>
-  <div id="container" class="container">
-    <div i18n-content="slowDescription"></div>
+  <div id="container">
+    <div>$i18n{slowDescription}</div>
     <br>
-    <div i18n-values=".innerHTML:slowWarning"></div>
-    <div id="container-inner" width=100% class="container-inner">
-      <button id="slow-disable" i18n-content="slowDisable" hidden></button>
-      <button id="slow-enable" i18n-content="slowEnable" hidden></button>
+    <div>$i18nRaw{slowWarning}</div>
+    <div id="container-inner">
+      <button id="slow-disable" hidden>$i18n{slowDisable}</button>
+      <button id="slow-enable" hidden>$i18n{slowEnable}</button>
     </div>
   </div>
-<script src="chrome://resources/js/i18n_template.js"></script>
 </body>
 </html>
diff --git a/chrome/browser/ui/webui/chromeos/slow_ui.cc b/chrome/browser/ui/webui/chromeos/slow_ui.cc
index 2e5b4c35..614813d 100644
--- a/chrome/browser/ui/webui/chromeos/slow_ui.cc
+++ b/chrome/browser/ui/webui/chromeos/slow_ui.cc
@@ -49,9 +49,10 @@
   source->AddLocalizedString("slowDescription", IDS_SLOW_DESCRIPTION);
   source->AddLocalizedString("slowWarning", IDS_SLOW_WARNING);
 
-  source->SetJsonPath("strings.js");
   source->AddResourcePath("slow.js", IDR_SLOW_JS);
+  source->AddResourcePath("slow.css", IDR_SLOW_CSS);
   source->SetDefaultResource(IDR_SLOW_HTML);
+  source->UseGzip();
   return source;
 }