gdiplus: Add a stub for GdipSetImageAttributesGamma.

dlls/gdiplus/gdiplus.spec

@@ -524,7 +524,7 @@
 @ stdcall GdipSetImageAttributesCachedBackground(ptr long)
 @ stdcall GdipSetImageAttributesColorKeys(ptr long long long long)
 @ stdcall GdipSetImageAttributesColorMatrix(ptr long long ptr ptr long)
-@ stub GdipSetImageAttributesGamma
+@ stdcall GdipSetImageAttributesGamma(ptr long long long)
 @ stub GdipSetImageAttributesNoOp
 @ stub GdipSetImageAttributesOutputChannel
 @ stub GdipSetImageAttributesOutputChannelColorProfile

dlls/gdiplus/imageattributes.c

@@ -101,3 +101,14 @@ GpStatus WINGDIPAPI GdipSetImageAttributesCachedBackground(GpImageAttributes *im
 
     return NotImplemented;
 }
+
+GpStatus WINGDIPAPI GdipSetImageAttributesGamma(GpImageAttributes *imageAttr,
+    ColorAdjustType type, BOOL enableFlag, REAL gamma)
+{
+    static int calls;
+
+    if(!(calls++))
+        FIXME("not implemented\n");
+
+    return NotImplemented;
+}