INPUT/TEXTAREA elements: Dispatch 'select' event only if text selection is changed.

third_party/WebKit/Source/core/html/TextControlElement.h

Index: third_party/WebKit/Source/core/html/TextControlElement.h
diff --git a/third_party/WebKit/Source/core/html/TextControlElement.h b/third_party/WebKit/Source/core/html/TextControlElement.h
index c7ad473554c4d91c23ff80955f9c0b4a44d981c6..8667c1ff259bf92e819da9fa2c7c120b14fa2c63 100644
--- a/third_party/WebKit/Source/core/html/TextControlElement.h
+++ b/third_party/WebKit/Source/core/html/TextControlElement.h
@@ -47,6 +47,11 @@ enum TextFieldEventBehavior {
   DispatchInputAndChangeEvent
 };
 
+enum class TextControlSetValueSelection {
+  kSetSelectionToEnd,

[yoichio, 2017/03/07 09:00:56]

Why do you use another coding style to above enums?

[tkent, 2017/03/07 09:27:34]

kFooBar is the standard naming convention.  FooBar style will be disappear soon.

+  kDoNotSet,
+};
+
 class CORE_EXPORT TextControlElement : public HTMLFormControlElementWithState {
  public:
   // Common flag for HTMLInputElement::tooLong(),
@@ -124,8 +129,11 @@ class CORE_EXPORT TextControlElement : public HTMLFormControlElementWithState {
   void setChangedSinceLastFormControlChangeEvent(bool);
 
   virtual String value() const = 0;
-  virtual void setValue(const String&,
-                        TextFieldEventBehavior = DispatchNoEvent) = 0;
+  virtual void setValue(
+      const String&,
+      TextFieldEventBehavior = DispatchNoEvent,
+      TextControlSetValueSelection =
+          TextControlSetValueSelection::kSetSelectionToEnd) = 0;
 
   HTMLElement* innerEditorElement() const;
 
@@ -160,14 +168,10 @@ class CORE_EXPORT TextControlElement : public HTMLFormControlElementWithState {
   unsigned computeSelectionStart() const;
   unsigned computeSelectionEnd() const;
   TextFieldSelectionDirection computeSelectionDirection() const;
-  void cacheSelection(unsigned start,
+  // Returns true if cached values and arguments are not same.
+  bool cacheSelection(unsigned start,
                       unsigned end,
-                      TextFieldSelectionDirection direction) {
-    DCHECK_LE(start, end);
-    m_cachedSelectionStart = start;
-    m_cachedSelectionEnd = end;
-    m_cachedSelectionDirection = direction;
-  }
+                      TextFieldSelectionDirection);
   static unsigned indexForPosition(HTMLElement* innerEditor, const Position&);
 
   void dispatchFocusEvent(Element* oldFocusedElement,