Implement <webview> droplink event

extensions/renderer/resources/guest_view/web_view_events.js

 // Copyright 2014 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.
 
 // Event management for WebView.
 
 var DeclarativeWebRequestSchema =
     requireNative('schema_registry').GetSchema('declarativeWebRequest');
 var EventBindings = require('event_bindings');
 var IdGenerator = requireNative('id_generator');
@@ skipping 40 matching lines @@
     fields: []
   },
   'dialog': {
     cancelable: true,
     customHandler: function(handler, event, webViewEvent) {
       handler.handleDialogEvent(event, webViewEvent);
     },
     evt: CreateEvent('webViewInternal.onDialog'),
     fields: ['defaultPromptText', 'messageText', 'messageType', 'url']
   },
+  'droplink': {
+    evt: CreateEvent('webViewInternal.onDropLink'),
+    fields: ['url']
+  },
   'exit': {
     evt: CreateEvent('webViewInternal.onExit'),
     fields: ['processId', 'reason']
   },
   'findupdate': {
     evt: CreateEvent('webViewInternal.onFindReply'),
     fields: [
       'searchText',
       'numberOfMatches',
       'activeMatchOrdinal',
@@ skipping 254 matching lines @@
       this.webViewImpl, event, webViewEvent);
 };
 
 WebViewEvents.prototype.handleSizeChangedEvent = function(
     event, webViewEvent) {
   this.webViewImpl.onSizeChanged(webViewEvent);
 };
 
 exports.WebViewEvents = WebViewEvents;
 exports.CreateEvent = CreateEvent;