Avoid redundant initialization of GraphicsContextState.

Source/platform/graphics/GraphicsContextState.h

 // Copyright (C) 2013 Google Inc. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //    * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //    * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
@@ skipping 28 matching lines @@
 #include "third_party/skia/include/core/SkColorFilter.h"
 #include "third_party/skia/include/core/SkPaint.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/RefPtr.h"
 
 namespace WebCore {
 
 // Encapsulates the state information we store for each pushed graphics state.
 // Only GraphicsContext can use this class.
 class PLATFORM_EXPORT GraphicsContextState FINAL {
-    WTF_MAKE_NONCOPYABLE(GraphicsContextState);
 public:
     static PassOwnPtr<GraphicsContextState> create()

[f(malita), 2014/05/27 18:16:44]

Let's update this instead: create(const GraphicsContextState& other).

     {
         return adoptPtr(new GraphicsContextState());
     }
 
-    void copy(GraphicsContextState*);
+    static PassOwnPtr<GraphicsContextState> createAndCopy(const GraphicsContextState* other)

[f(malita), 2014/05/27 18:16:44]

realizePaintSave() is the only user of create(), no need to add a new variant.

[Dominik Grewe, 2014/05/27 19:59:22]

The GraphicsContext constructor also calls create, so we want to keep it.

+    {
+        return adoptPtr(new GraphicsContextState(*other));
+    }
+
+    void copy(const GraphicsContextState*);

[f(malita), 2014/05/27 18:16:44]

Let's also update this to a const reference argument.

[Dominik Grewe, 2014/05/27 19:59:22]

Will do.

 
     // SkPaint objects that reflect the current state. If the length of the
     // path to be stroked is known, pass it in for correct dash or dot placement.
     const SkPaint& strokePaint(int strokedPathLength = 0) const;
     const SkPaint& fillPaint() const;
 
     uint16_t saveCount() const { return m_saveCount; }
     void incrementSaveCount() { ++m_saveCount; }
     void decrementSaveCount() { --m_saveCount; }
 
@@ skipping 68 matching lines @@
     void setShouldAntialias(bool);
 
     bool shouldSmoothFonts() const { return m_shouldSmoothFonts; }
     void setShouldSmoothFonts(bool shouldSmoothFonts) { m_shouldSmoothFonts = shouldSmoothFonts; }
 
     bool shouldClampToSourceRect() const { return m_shouldClampToSourceRect; }
     void setShouldClampToSourceRect(bool shouldClampToSourceRect) { m_shouldClampToSourceRect = shouldClampToSourceRect; }
 
 private:
     GraphicsContextState();
+    explicit GraphicsContextState(const GraphicsContextState&);
 
     // Helper function for applying the state's alpha value to the given input
     // color to produce a new output color.
     SkColor applyAlpha(SkColor c) const
     {
         int a = SkAlphaMul(SkColorGetA(c), m_alpha);
         return (c & 0x00FFFFFF) | (a << 24);
     }
 
     // These are mutbale to enable gradient updates when the paints are fetched for use.
@@ skipping 23 matching lines @@
     uint16_t m_saveCount;
 
     bool m_shouldAntialias : 1;
     bool m_shouldSmoothFonts : 1;
     bool m_shouldClampToSourceRect : 1;
 };
 
 } // namespace WebCore
 
 #endif // GraphicsContextState_h