Revert of Avoid style clobbering in setCompositionFromExistingText.

Source/core/editing/FrameSelection.cpp

Index: Source/core/editing/FrameSelection.cpp
diff --git a/Source/core/editing/FrameSelection.cpp b/Source/core/editing/FrameSelection.cpp
index f60ecb7d607182f32bb3e02dcd95eccebb71848a..2969141df7194bf5aff4338d959ad7d23ab325dd 100644
--- a/Source/core/editing/FrameSelection.cpp
+++ b/Source/core/editing/FrameSelection.cpp
@@ -314,10 +314,8 @@
     // boundary, selection for the DOM tree is shrunk while that for the
     // composed tree is not. Additionally, this case occurs in some edge cases.
     // See also: editing/pasteboard/4076267-3.html
-    if (VisibleSelection::InDOMTree::equalSelections(oldSelection, m_selection)) {
-        m_frame->inputMethodController().cancelCompositionIfSelectionIsInvalid();
-        return;
-    }
+    if (VisibleSelection::InDOMTree::equalSelections(oldSelection, m_selection))
+        return;
     m_frame->editor().respondToChangedSelection(oldSelection, options);
     if (userTriggered == UserTriggered) {
         ScrollAlignment alignment;