Adds extension events for custom dictionary load/change.

chrome/common/extensions/api/input_method_private.json

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [
   {
     "namespace": "inputMethodPrivate",
     "description": "none",
     "functions": [
       {
@@ skipping 153 matching lines @@
               "type": "object",
               "properties": {
                 "x": {"type": "integer"},
                 "y": {"type": "integer"},
                 "w": {"type": "integer"},
                 "h": {"type": "integer"}
               }
             }
           }
         ]
+      }, {
+        "name": "onDictionaryLoaded",
+        "type": "function",
+        "description": "Fired when the custom spelling dictionary is loaded.",
+        "parameters": []
+      }, {
+        "name": "onDictionaryChanged",
+        "type": "function",
+        "description": "Fired when words are added or removed from the custom spelling dictionary.",
+        "parameters": [
+          {
+            "name": "added",
+            "type": "array",
+            "description": "List of added words.",
+            "items": {
+              "type": "string"
+            }
+          }, {
+            "name": "removed",
+            "type": "array",
+            "description": "List of removed words.",
+            "items": {
+              "type": "string"
+            }
+          }
+        ]
       }
     ]
   }
 ]