Make a SharedGraphics directory for classes shared between Kernel and LibGUI.

SharedGraphics/Size.h

@@ -0,0 +1,31 @@
+#pragma once
+
+struct GUI_Size;
+
+class Size {
+public:
+    Size() { }
+    Size(int w, int h) : m_width(w), m_height(h) { }
+    Size(const GUI_Size&);
+
+    bool is_empty() const { return !m_width || !m_height; }
+
+    int width() const { return m_width; }
+    int height() const { return m_height; }
+
+    void set_width(int w) { m_width = w; }
+    void set_height(int h) { m_height = h; }
+
+    bool operator==(const Size& other) const
+    {
+        return m_width == other.m_width &&
+               m_height == other.m_height;
+    }
+
+    operator GUI_Size() const;
+
+private:
+    int m_width { 0 };
+    int m_height { 0 };
+};
+