Revert of [DevTools] Show icon in top toolbar when Node target is available

third_party/WebKit/Source/devtools/front_end/sources/ThreadsSidebarPane.js

Index: third_party/WebKit/Source/devtools/front_end/sources/ThreadsSidebarPane.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sources/ThreadsSidebarPane.js b/third_party/WebKit/Source/devtools/front_end/sources/ThreadsSidebarPane.js
index 80095851c8de7638e651bcc4674cf86009698e85..2c425989014a98ad8bdac4e3fdb29cc485090a8e 100644
--- a/third_party/WebKit/Source/devtools/front_end/sources/ThreadsSidebarPane.js
+++ b/third_party/WebKit/Source/devtools/front_end/sources/ThreadsSidebarPane.js
@@ -14,7 +14,14 @@
     this._list = new UI.ListControl(this, UI.ListMode.NonViewport);
     this.contentElement.appendChild(this._list.element);
 
+    this._availableNodeTargetsElement = this.contentElement.createChild('div', 'hidden available-node-targets');
+
     UI.context.addFlavorChangeListener(SDK.Target, this._targetFlavorChanged, this);
+
+    SDK.targetManager.addEventListener(
+        SDK.TargetManager.Events.AvailableNodeTargetsChanged, this._availableNodeTargetsChanged, this);
+    this._availableNodeTargetsChanged();
+
     SDK.targetManager.observeModels(SDK.DebuggerModel, this);
   }
 
@@ -23,7 +30,27 @@
    */
   static shouldBeShown() {
     var minJSTargets = Runtime.queryParam('nodeFrontend') ? 1 : 2;
-    return SDK.targetManager.models(SDK.DebuggerModel).length >= minJSTargets;
+    if (SDK.targetManager.models(SDK.DebuggerModel).length >= minJSTargets)
+      return true;
+    return !!SDK.targetManager.availableNodeTargetsCount();
+  }
+
+  _availableNodeTargetsChanged() {
+    var count = SDK.targetManager.availableNodeTargetsCount();
+    if (!count) {
+      this._availableNodeTargetsElement.classList.add('hidden');
+      return;
+    }
+    this._availableNodeTargetsElement.removeChildren();
+    this._availableNodeTargetsElement.createTextChild(
+        count === 1 ? Common.UIString('Node instance available.') :
+                      Common.UIString('%d Node instances available.', count));
+    var link = this._availableNodeTargetsElement.createChild('span', 'link');
+    link.textContent = Common.UIString('Connect');
+    link.addEventListener('click', () => {
+      InspectorFrontendHost.openNodeFrontend();
+    }, false);
+    this._availableNodeTargetsElement.classList.remove('hidden');
   }
 
   /**