fixup! Bug 31286: Implementation of bridge, proxy, and firewall settings in...

fixup! Bug 31286: Implementation of bridge, proxy, and firewall settings in about:preferences#connection

Bug 42662: Revert changes to main.inc.xhtml and main.js that remove the
firefox connection settings.

browser/components/preferences/main.inc.xhtml

@@ -797,4 +797,53 @@
     />
   </hbox>
 </groupbox>
+
+<hbox id="networkProxyCategory"
+      class="subcategory"
+      hidden="true"
+      data-category="paneGeneral">
+  <html:h1 data-l10n-id="network-settings-title"/>
+</hbox>
+
+<!-- Network Settings-->
+<groupbox id="connectionGroup" data-category="paneGeneral" hidden="true">
+  <label class="search-header" hidden="true"><html:h2 data-l10n-id="network-settings-title"/></label>
+
+  <hbox align="center"
+      data-subcategory="netsettings">
+    <description flex="1" control="connectionSettings">
+      <html:span id="connectionSettingsDescription"/>
+      <html:a is="moz-support-link"
+            data-l10n-id="network-proxy-connection-learn-more"
+            support-page="prefs-connection-settings"
+      />
+    </description>
+    <separator orient="vertical"/>
+    <button id="connectionSettings"
+            is="highlightable-button"
+            class="accessory-button"
+            data-l10n-id="network-proxy-connection-settings"
+            search-l10n-ids="
+              connection-window2.title,
+              connection-proxy-option-no.label,
+              connection-proxy-option-auto.label,
+              connection-proxy-option-system.label,
+              connection-proxy-option-wpad.label,
+              connection-proxy-option-manual.label,
+              connection-proxy-http,
+              connection-proxy-https,
+              connection-proxy-http-port,
+              connection-proxy-socks,
+              connection-proxy-socks4,
+              connection-proxy-socks5,
+              connection-proxy-noproxy,
+              connection-proxy-noproxy-desc,
+              connection-proxy-https-sharing.label,
+              connection-proxy-autotype.label,
+              connection-proxy-reload.label,
+              connection-proxy-autologin-checkbox.label,
+              connection-proxy-socks-remote-dns.label,
+          " />
+  </hbox>
+</groupbox>
 </html:template>

browser/components/preferences/main.js

@@ -313,6 +313,8 @@ var gMainPane = {
     });
     this.updatePerformanceSettingsBox({ duringChangeEvent: false });
     this.displayUseSystemLocale();
+    this.updateProxySettingsUI();
+    initializeProxyUI(gMainPane);
 
     if (Services.prefs.getBoolPref("intl.multilingual.enabled")) {
       gMainPane.initPrimaryBrowserLanguageUI();
@@ -515,6 +517,11 @@ var gMainPane = {
       "change",
       gMainPane.updateHardwareAcceleration.bind(gMainPane)
     );
+    setEventListener(
+      "connectionSettings",
+      "command",
+      gMainPane.showConnections
+    );
     setEventListener(
       "browserContainersCheckbox",
       "command",