Remove logic to reset input method more than needed

third_party/WebKit/Source/core/editing/InputMethodController.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 107 matching lines @@
 } // anonymous namespace
 
 InputMethodController* InputMethodController::create(LocalFrame& frame)
 {
     return new InputMethodController(frame);
 }
 
 InputMethodController::InputMethodController(LocalFrame& frame)
     : m_frame(&frame)
     , m_isDirty(false)
-    , m_hasComposition(false)
 {
 }
 
 bool InputMethodController::hasComposition() const
 {
-    return m_hasComposition;
+    return m_compositionRange && !m_compositionRange->collapsed();
 }
 
 inline Editor& InputMethodController::editor() const
 {
     return frame().editor();
 }
 
 void InputMethodController::clear()
 {
-    m_hasComposition = false;
     if (m_compositionRange) {
         m_compositionRange->setStart(frame().document(), 0);
         m_compositionRange->collapse(true);
     }
     frame().document()->markers().removeMarkers(DocumentMarker::Composition);
     m_isDirty = false;
 }
 
 void InputMethodController::documentDetached()
 {
@@ skipping 159 matching lines @@
         return;
 
     // An open typing command that disagrees about current selection would cause
     // issues with typing later on.
     TypingCommand::closeTyping(m_frame);
 
     // No DOM update after 'compositionend'.
     dispatchCompositionEndEvent(frame(), emptyString());
 }
 
-void InputMethodController::cancelCompositionIfSelectionIsInvalid()
-{
-    if (!hasComposition() || editor().preventRevealSelection())
-        return;
-
-    // Check if selection start and selection end are valid.
-    FrameSelection& selection = frame().selection();
-    if (!selection.isNone() && !m_compositionRange->collapsed()) {
-        if (selection.start().compareTo(m_compositionRange->startPosition()) >= 0
-            && selection.end().compareTo(m_compositionRange->endPosition()) <= 0)
-            return;
-    }
-
-    cancelComposition();
-    frame().chromeClient().didCancelCompositionOnSelectionChange();

[yosin_UTC9, 2016/09/28 03:38:50]

Could you add TODO comment in "ChromeClient.h" to get rid of
|didCancelCompositionOnSelectionChange()|?

[Changwan Ryu, 2016/09/28 06:20:12]

My bad, I just went ahead and removed it.

-}
-
 void InputMethodController::setComposition(const String& text, const Vector<CompositionUnderline>& underlines, int selectionStart, int selectionEnd)
 {
     Editor::RevealSelectionScope revealSelectionScope(&editor());
 
     // Updates styles before setting selection for composition to prevent
     // inserting the previous composition text into text nodes oddly.
     // See https://bugs.webkit.org/show_bug.cgi?id=46868
     frame().document()->updateStyleAndLayoutTree();
 
     selectComposition();
@@ skipping 78 matching lines @@
     Node* extentNode = extent.anchorNode();
     if (baseNode != extentNode)
         return;
 
     unsigned extentOffset = extent.computeOffsetInContainerNode();
     unsigned baseOffset = base.computeOffsetInContainerNode();
     if (baseOffset + text.length() != extentOffset)
         return;
 
     m_isDirty = true;
-    m_hasComposition = true;
     if (!m_compositionRange)
         m_compositionRange = Range::create(baseNode->document());
     m_compositionRange->setStart(baseNode, baseOffset);
     m_compositionRange->setEnd(baseNode, extentOffset);
 
     if (baseNode->layoutObject())
         baseNode->layoutObject()->setShouldDoFullPaintInvalidation();
 
     // TODO(xiaochengh): The use of updateStyleAndLayoutIgnorePendingStylesheets
     // needs to be audited. see http://crbug.com/590369 for more details.
@@ skipping 40 matching lines @@
 
     for (const auto& underline : underlines) {
         unsigned underlineStart = compositionStart + underline.startOffset();
         unsigned underlineEnd = compositionStart + underline.endOffset();
         EphemeralRange ephemeralLineRange = PlainTextRange(underlineStart, underlineEnd).createRange(*editable);
         if (ephemeralLineRange.isNull())
             continue;
         frame().document()->markers().addCompositionMarker(ephemeralLineRange.startPosition(), ephemeralLineRange.endPosition(), underline.color(), underline.thick(), underline.backgroundColor());
     }
 
-    m_hasComposition = true;
     if (!m_compositionRange)
         m_compositionRange = Range::create(range.document());
     m_compositionRange->setStart(range.startPosition());
     m_compositionRange->setEnd(range.endPosition());
 }
 
 EphemeralRange InputMethodController::compositionEphemeralRange() const
 {
     if (!hasComposition())
         return EphemeralRange();
@@ skipping 118 matching lines @@
     TypingCommand::deleteSelection(*frame().document());
 }
 
 DEFINE_TRACE(InputMethodController)
 {
     visitor->trace(m_frame);
     visitor->trace(m_compositionRange);
 }
 
 } // namespace blink