Bug 676268 - Part 2. Use editor API instead of accessing clipboard directly r=geckoview-reviewers,snorp

Actually, Fennec accesses clipboard directly when using action bar. To allow
`text/html` mime type, we should use editor API instead.

Also, Fennec doesn't fire clipboard event for copy and cut since it doesn't
use editor API (or `cmd_*` command). So we will be fixed by using editor API.

GeckoView uses `cmd_*` command, so this doesn't occur on GV.

Differential Revision: https://phabricator.services.mozilla.com/D22886

--HG--
extra : moz-landing-system : lando

mobile/android/modules/ActionBarHandler.jsm

@@ -1,4 +1,5 @@
 // -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+/* vim: set ts=2 et sw=2 tw=80 filetype=javascript: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
@@ -442,18 +443,11 @@ var ActionBarHandler = {
       },
 
       action: function(element, win) {
-        // First copy the selection text to the clipboard.
-        let selectedText = ActionBarHandler._getSelectedText();
-        let clipboard = Cc["@mozilla.org/widget/clipboardhelper;1"].
-          getService(Ci.nsIClipboardHelper);
-        clipboard.copyString(selectedText);
+        ActionBarHandler._getEditor(element, win).cut();
 
         let msg = Strings.browser.GetStringFromName("selectionHelper.textCopied");
         Snackbars.show(msg, Snackbars.LENGTH_LONG);
 
-        // Then cut the selection text.
-        ActionBarHandler._getSelection(element, win).deleteFromDocument();
-
         ActionBarHandler._uninit();
         UITelemetry.addEvent("action.1", "actionbar", null, "cut");
       },
@@ -480,10 +474,7 @@ var ActionBarHandler = {
       },
 
       action: function(element, win) {
-        let selectedText = ActionBarHandler._getSelectedText();
-        let clipboard = Cc["@mozilla.org/widget/clipboardhelper;1"].
-          getService(Ci.nsIClipboardHelper);
-        clipboard.copyString(selectedText);
+        ActionBarHandler._getEditor(element, win).copy();
 
         let msg = Strings.browser.GetStringFromName("selectionHelper.textCopied");
         Snackbars.show(msg, Snackbars.LENGTH_LONG);