bluetooth: Basic browser tests for chrome://bluetooth-internals.

chrome/browser/resources/bluetooth_internals/interfaces.js

Index: chrome/browser/resources/bluetooth_internals/interfaces.js
diff --git a/chrome/browser/resources/bluetooth_internals/interfaces.js b/chrome/browser/resources/bluetooth_internals/interfaces.js
index 92366c289bf952c3f3dd1cf653ac10454fc5dd4e..061bbf89915234b50683a870043325b4ec90849b 100644
--- a/chrome/browser/resources/bluetooth_internals/interfaces.js
+++ b/chrome/browser/resources/bluetooth_internals/interfaces.js
@@ -44,7 +44,18 @@ cr.define('interfaces', function() {
     });
   }
 
+  /**
+  * Overriden by tests to give them a chance to setup a fake Mojo browser proxy
+  * before any other code executes.
+  * @return {!Promise} A promise firing once necessary setup has been completed.
+  */
+  var setupFn = window.setupFn || function() { return Promise.resolve(); };
+
+  function initialize() {
+    return setupFn().then(initializeProxies);
+  }
+
   return {
-    initialize: initializeProxies,
+    initialize: initialize,
   };
 });