Context menus for text fields in platform apps should show available actions (copy, paste, etc).

chrome/test/data/extensions/platform_apps/context_menu/test.js

Index: chrome/test/data/extensions/platform_apps/context_menu/test.js
diff --git a/chrome/test/data/extensions/platform_apps/context_menu/test.js b/chrome/test/data/extensions/platform_apps/context_menu/test.js
index c3280a02b873831a8480028c265dd9a7db86242d..c31574293830e07e01fa7dc54e3095262d5d47c9 100644
--- a/chrome/test/data/extensions/platform_apps/context_menu/test.js
+++ b/chrome/test/data/extensions/platform_apps/context_menu/test.js
@@ -6,6 +6,7 @@ chrome.app.runtime.onLaunched.addListener(function() {
   chrome.contextMenus.create({
         id: 'id1',
         title: 'Extension Item 1',
+        contexts: ['all']
       },
       function() {
         chrome.app.window.create('main.html', {}, function() {});