Add an API for hosted apps to check their install and running states.

chrome/renderer/resources/extensions/app_custom_bindings.js

Index: chrome/renderer/resources/extensions/app_custom_bindings.js
diff --git a/chrome/renderer/resources/extensions/app_custom_bindings.js b/chrome/renderer/resources/extensions/app_custom_bindings.js
index 1c8d1cbd98457f6870913fac5fe913956af9a80c..16db32de4bef9ee55cc8e62dd58e77b600e97cc4 100644
--- a/chrome/renderer/resources/extensions/app_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/app_custom_bindings.js
@@ -11,7 +11,8 @@ var app = {
   getIsInstalled: appNatives.GetIsInstalled,
   install: appNatives.Install,
   getDetails: appNatives.GetDetails,
-  getDetailsForFrame: appNatives.GetDetailsForFrame
+  getDetailsForFrame: appNatives.GetDetailsForFrame,
+  runningState: appNatives.GetRunningState
 };
 
 // Tricky; "getIsInstalled" is actually exposed as the getter "isInstalled",
@@ -30,6 +31,13 @@ var chromeHiddenApp = {
       callbacks[callbackId](channelId, error);
       delete callbacks[callbackId];
     }
+  },
+
+  onInstallStateResponse: function(state, callbackId) {
+    if (callbackId) {
+      callbacks[callbackId](state);
+      delete callbacks[callbackId];
+    }
   }
 };
 
@@ -53,6 +61,12 @@ var appNotifications = {
   }
 };
 
+app.installState = function getInstallState(callback) {
+  var callbackId = nextCallbackId++;
+  callbacks[callbackId] = callback;
+  appNatives.GetInstallState(callbackId);
+};
+
 // These must match the names in InstallAppBindings() in
 // extension_dispatcher.cc.
 exports.chromeApp = app;