CSS4: Implement :placeholder-shown pseudo class

Source/core/html/HTMLTextFormControlElement.h

Index: Source/core/html/HTMLTextFormControlElement.h
diff --git a/Source/core/html/HTMLTextFormControlElement.h b/Source/core/html/HTMLTextFormControlElement.h
index 906661dfbc87adbeddf081002595d84ecfed4abc..7bc3ec211383a955bd1a2d5978b492771595884b 100644
--- a/Source/core/html/HTMLTextFormControlElement.h
+++ b/Source/core/html/HTMLTextFormControlElement.h
@@ -60,11 +60,11 @@ public:
     InsertionNotificationRequest insertedInto(ContainerNode*) override;
 
     // The derived class should return true if placeholder processing is needed.
+    bool isPlaceholderVisible() const { return m_isPlaceholderVisible; }

[esprehn, 2015/08/21 10:18:10]

virtual, HTMLInputElement and HTMLTextAreaElement should implement it and use
better storage.

[ramya.v, 2015/08/25 10:24:45]

Done.

     virtual bool supportsPlaceholder() const = 0;
     String strippedPlaceholder() const;
-    bool placeholderShouldBeVisible() const;
     HTMLElement* placeholderElement() const;
-    void updatePlaceholderVisibility(bool);
+    void updatePlaceholderVisibility();
 
     VisiblePosition visiblePositionForIndex(int) const;
     int indexForVisiblePosition(const VisiblePosition&) const;
@@ -154,12 +154,15 @@ private:
     // Called in dispatchBlurEvent(), after placeholder process, before calling parent's dispatchBlurEvent().
     virtual void handleBlurEvent() { }
 
+    bool placeholderShouldBeVisible() const;
+
     String m_textAsOfLastFormControlChangeEvent;
     bool m_lastChangeWasUserEdit;
 
     int m_cachedSelectionStart;
     int m_cachedSelectionEnd;
     TextFieldSelectionDirection m_cachedSelectionDirection;
+    bool m_isPlaceholderVisible;

[esprehn, 2015/08/21 10:18:10]

This should be on HTMLInputElement and merged with the bitfields.

[ramya.v, 2015/08/25 10:24:45]

Done.

 };
 
 inline bool isHTMLTextFormControlElement(const Element& element)