Avoid redundant initialization of GraphicsContextState.

Source/platform/graphics/GraphicsContextState.h

Index: Source/platform/graphics/GraphicsContextState.h
diff --git a/Source/platform/graphics/GraphicsContextState.h b/Source/platform/graphics/GraphicsContextState.h
index ee1c625da3c9d9862baad526443892fcdd6afa7a..a70ab2ed7c190109d72106ca55077985eac2721c 100644
--- a/Source/platform/graphics/GraphicsContextState.h
+++ b/Source/platform/graphics/GraphicsContextState.h
@@ -46,14 +46,18 @@ 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.
@@ -142,6 +146,7 @@ public:
 
 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.