Avoid style clobbering in setCompositionFromExistingText. (2nd land)

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 3d8b889617d08372303dd62224d25a45c39cb286..1944215af57c1969e12890c847aa1db6bea2c2e7 100644
--- a/Source/core/editing/FrameSelection.cpp
+++ b/Source/core/editing/FrameSelection.cpp
@@ -314,8 +314,10 @@ void FrameSelection::setSelection(const VisibleSelection& newSelection, SetSelec
     // 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))
+    if (VisibleSelection::InDOMTree::equalSelections(oldSelection, m_selection)) {
+        m_frame->inputMethodController().cancelCompositionIfSelectionIsInvalid();
         return;
+    }
     m_frame->editor().respondToChangedSelection(oldSelection, options);
     if (userTriggered == UserTriggered) {
         ScrollAlignment alignment;