Add encounteredError() to AssociatedInterfacePtrController.

mojo/public/js/associated_bindings.js

Index: mojo/public/js/associated_bindings.js
diff --git a/mojo/public/js/associated_bindings.js b/mojo/public/js/associated_bindings.js
index 18ac452daf599c11d1a3e8db0ed0e78a90a0a7ac..3935dee8d1d5007351c1d4a49fa4e84c61506009 100644
--- a/mojo/public/js/associated_bindings.js
+++ b/mojo/public/js/associated_bindings.js
@@ -116,6 +116,13 @@ define("mojo/public/js/associated_bindings", [
     this.reset();
   };
 
+  // Indicates whether an error has been encountered. If true, method calls
+  // on this interface will be dropped (and may already have been dropped).
+  AssociatedInterfacePtrController.prototype.encounteredError = function() {
+    return this.interfaceEndpointClient_ ?
+        this.interfaceEndpointClient_.encounteredError : false;
+  };
+
   AssociatedInterfacePtrController.prototype.setConnectionErrorHandler =
       function(callback) {
     if (!this.isBound()) {