Plumb listenerIDs correctly for events that clobber chrome.Event.prototype.dispatch.

chrome/renderer/resources/extensions/input.ime_custom_bindings.js

Index: chrome/renderer/resources/extensions/input.ime_custom_bindings.js
diff --git a/chrome/renderer/resources/extensions/input.ime_custom_bindings.js b/chrome/renderer/resources/extensions/input.ime_custom_bindings.js
index 7a64e9dcf736b1a880e9dfcf2bc400702041e657..204a9e0ae81a9c136fe25fc634ac8aabc99f4232 100644
--- a/chrome/renderer/resources/extensions/input.ime_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/input.ime_custom_bindings.js
@@ -8,29 +8,16 @@
 var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
 
 chromeHidden.registerCustomHook('input.ime', function() {
-  chrome.input.ime.onKeyEvent.dispatch = function(engineID, keyData) {
-    var args = Array.prototype.slice.call(arguments);
-    if (this.validate_) {
-      var validationErrors = this.validate_(args);
-      if (validationErrors) {
-        chrome.input.ime.eventHandled(requestId, false);
-        return validationErrors;
-      }
-    }
-    if (this.listeners_.length > 1) {
-      console.error('Too many listeners for onKeyEvent: ' + e.stack);
-      chrome.input.ime.eventHandled(requestId, false);
-      return;
-    }
-    for (var i = 0; i < this.listeners_.length; i++) {
-      try {
-        var requestId = keyData.requestId;
-        var result = this.listeners_[i].callback.apply(null, args);
-        chrome.input.ime.eventHandled(requestId, result);
-      } catch (e) {
-        console.error('Error in event handler for onKeyEvent: ' + e.stack);
-        chrome.input.ime.eventHandled(requestId, false);
-      }
+  chrome.input.ime.onKeyEvent.dispatchToListener = function(callback, args) {
+    var engineID = args[0];
+    var keyData = args[1];
+
+    var result = false;
+    try {
+      result = chrome.Event.prototype.dispatchToListener(callback, args);
+    } catch (e) {
+      console.error('Error in event handler for onKeyEvent: ' + e.stack);
     }
+    chrome.input.ime.eventHandled(keyData.requestId, result);
   };
 });