Enumerate the return value of dispatchEvent so it is clear.

third_party/WebKit/Source/core/editing/SelectionEditor.h

Index: third_party/WebKit/Source/core/editing/SelectionEditor.h
diff --git a/third_party/WebKit/Source/core/editing/SelectionEditor.h b/third_party/WebKit/Source/core/editing/SelectionEditor.h
index a05816ad3bc530ddb93adb4d3d83c49cbf6dea6d..65cfd8370fb872a8ca503a025cf7c313053f0a90 100644
--- a/third_party/WebKit/Source/core/editing/SelectionEditor.h
+++ b/third_party/WebKit/Source/core/editing/SelectionEditor.h
@@ -27,6 +27,7 @@
 #define SelectionEditor_h
 
 #include "core/editing/FrameSelection.h"
+#include "core/events/EventTarget.h"
 
 namespace blink {
 
@@ -109,7 +110,7 @@ private:
     void stopObservingVisibleSelectionChangeIfNecessary();
 
     LayoutUnit lineDirectionPointForBlockDirectionNavigation(EPositionType);
-    bool dispatchSelectStart();
+    WebInputEventResult dispatchSelectStart();
 
     RawPtrWillBeMember<FrameSelection> m_frameSelection;