feat(propertiesPane): add back properties pane

Closes #160

devtoolsBackground.js

@@ -1,8 +1,44 @@
 var panels = chrome.devtools.panels;
 
+// The function below is executed in the context of the inspected page.
+
+var getPanelContents = function () {
+  if (window.angular && $0) {
+    //TODO: can we move this scope export into updateElementProperties
+    var scope = window.angular.element($0).scope();
+    // Export $scope to the console
+    window.$scope = scope;
+    return (function (scope) {
+      var panelContents = {
+        __private__: {}
+      };
+
+      for (prop in scope) {
+        if (scope.hasOwnProperty(prop)) {
+          if (prop.substr(0, 2) === '$$') {
+            panelContents.__private__[prop] = scope[prop];
+          } else {
+            panelContents[prop] = scope[prop];
+          }
+        }
+      }
+      return panelContents;
+    }(scope));
+  } else {
+    return {};
+  }
+};
+
+panels.elements.createSidebarPane(
+  "AngularJS Properties",
+  function (sidebar) {
+    panels.elements.onSelectionChanged.addListener(function updateElementProperties() {
+      sidebar.setExpression("(" + getPanelContents.toString() + ")()");
+    });
+  });
+
 var angularPanel = panels.create(
   "AngularJS",
   "img/angular.png",
   "panel/app.html"
 );
-