Privacy page: make metrics browser proxy a member

Bug: 1032584
Change-Id: I073bfe35e96c163e9f9b1812e4b31e1f89aa682d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2137390Reviewed-by: Esmael Elmoslimany <aee@chromium.org>
Commit-Queue: Rainhard Findling <rainhard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758058}

chrome/browser/resources/settings/privacy_page/BUILD.gn

@@ -587,7 +587,7 @@ polymer_modulizer("privacy_page") {
   auto_imports = settings_auto_imports + [
                    "ui/webui/resources/html/assert.html|assert",
                    "chrome/browser/resources/settings/route.html|routes",
-                   "chrome/browser/resources/settings/metrics_browser_proxy.html|PrivacyElementInteractions,MetricsBrowserProxyImpl",
+                   "chrome/browser/resources/settings/metrics_browser_proxy.html|PrivacyElementInteractions,MetricsBrowserProxy,MetricsBrowserProxyImpl",
                    "chrome/browser/resources/settings/privacy_page/privacy_page_browser_proxy.html|PrivacyPageBrowserProxy,PrivacyPageBrowserProxyImpl",
                    "chrome/browser/resources/settings/site_settings/site_settings_prefs_browser_proxy.html|SiteSettingsPrefsBrowserProxyImpl",
                    "chrome/browser/resources/settings/site_settings/constants.html|ContentSettingsTypes,CookieControlsMode,ChooserType",

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

@@ -281,6 +281,9 @@ cr.define('settings', function() {
     /** @private {?settings.PrivacyPageBrowserProxy} */
     browserProxy_: null,
 
+    /** @private {?settings.MetricsBrowserProxy} */
+    metricsBrowserProxy_: null,
+
     /** @override */
     ready() {
       this.ContentSettingsTypes = settings.ContentSettingsTypes;