MD Settings: show restart button when user toggles metrics reporting

chrome/browser/resources/settings/privacy_page/privacy_page.js

Index: chrome/browser/resources/settings/privacy_page/privacy_page.js
diff --git a/chrome/browser/resources/settings/privacy_page/privacy_page.js b/chrome/browser/resources/settings/privacy_page/privacy_page.js
index e2f2c045052fb973d4c9ea81ab5a3f295c55a787..90c43ba1c4115c99d95cb79f505c390d0ba707da 100644
--- a/chrome/browser/resources/settings/privacy_page/privacy_page.js
+++ b/chrome/browser/resources/settings/privacy_page/privacy_page.js
@@ -35,6 +35,8 @@ Polymer({
 <if expr="_google_chrome and not chromeos">
     /** @type {MetricsReporting} */

[dpapad, 2016/11/03 01:32:38]

?MetricsReporting

[Dan Beam, 2016/11/03 01:38:32]

this isn't initially null, it's undefined

/** @type {Thing} */
var blah;
this.getBlah().then(function(blah) {
  blah = newBlah;
});

doesn't have a ? and some people put ! even though it's technically |undefined
until success

     metricsReporting_: Object,
+
+    showRestart_: Boolean,
 </if>
 
     /** @private */
@@ -114,8 +116,17 @@ Polymer({
    * @private
    */
   setMetricsReporting_: function(metricsReporting) {
+    if (this.metricsReporting_) {
+      // TODO(dbeam): hide if changed back to the value Chrome started with.

[dpapad, 2016/11/03 01:32:38]

Eh, is that too hard to do now? Just need an extra boolean, right?

[Dan Beam, 2016/11/03 01:38:32]

to do correctly, we need to do this on chrome startup from the metrics code

see: how GPU acceleration works

+      this.showRestart_ = true;
+    }
     this.metricsReporting_ = metricsReporting;
   },
+
+  /** @private */
+  onRestartTap_: function() {
+    settings.LifetimeBrowserProxyImpl.getInstance().restart();
+  },
 </if>
 
 <if expr="_google_chrome">