Add support for Android spellcheck menu in Chrome/WebViews

third_party/WebKit/Source/core/events/InputEvent.h

 // Copyright 2016 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.
 
 #ifndef InputEvent_h
 #define InputEvent_h
 
 #include "core/clipboard/DataTransfer.h"
 #include "core/dom/Range.h"
 #include "core/dom/StaticRange.h"
@@ skipping 21 matching lines @@
     kInsertOrderedList,
     kInsertUnorderedList,
     kInsertHorizontalRule,
     kInsertFromPaste,
     kInsertFromDrop,
     kInsertFromYank,
     kInsertTranspose,
     kInsertReplacementText,
     kInsertCompositionText,
     // Deletion.
+    kDeleteByComposition,

[rlanday, 2017/06/06 21:06:01]

See the Input Events Level 2 working draft:
https://www.w3.org/TR/input-events-2/#interface-InputEvent-Attributes

My interpretation of the spec is that our use case falls under this:
"15. If the user expresses an intention to remove a part of the DOM in order to
recompose this part using IME, the inputType must be "deleteByComposition"."

     kDeleteWordBackward,
     kDeleteWordForward,
     kDeleteSoftLineBackward,
     kDeleteSoftLineForward,
     kDeleteHardLineBackward,
     kDeleteHardLineForward,
     kDeleteContentBackward,
     kDeleteContentForward,
     kDeleteByCut,
     kDeleteByDrag,
@@ skipping 80 matching lines @@
   explicit InputEventDispatchMediator(InputEvent*);
   InputEvent& Event() const;
   DispatchEventResult DispatchEvent(EventDispatcher&) const override;
 };
 
 DEFINE_EVENT_TYPE_CASTS(InputEvent);
 
 }  // namespace blink
 
 #endif  // InputEvent_h