gdiplus: Add stub for GdipGetImageThumbnail.

dlls/gdiplus/gdiplus.spec

@@ -295,7 +295,7 @@
 @ stdcall GdipGetImagePaletteSize(ptr ptr)
 @ stdcall GdipGetImagePixelFormat(ptr ptr)
 @ stdcall GdipGetImageRawFormat(ptr ptr)
-@ stub GdipGetImageThumbnail
+@ stdcall GdipGetImageThumbnail(ptr long long ptr ptr ptr)
 @ stdcall GdipGetImageType(ptr ptr)
 @ stdcall GdipGetImageVerticalResolution(ptr ptr)
 @ stdcall GdipGetImageWidth(ptr ptr)

dlls/gdiplus/image.c

@@ -1663,3 +1663,15 @@ GpStatus WINGDIPAPI GdipImageForceValidation(GpImage *image)
 
     return Ok;
 }
+
+/*****************************************************************************
+ * GdipGetImageThumbnail [GDIPLUS.@]
+ */
+GpStatus WINGDIPAPI GdipGetImageThumbnail(GpImage *image, UINT width, UINT height,
+                            GpImage **ret_image, GetThumbnailImageAbort cb,
+                            VOID * cb_data)
+{
+    FIXME("(%p %u %u %p %p %p) stub\n",
+        image, width, height, ret_image, cb, cb_data);
+    return NotImplemented;
+}

include/gdiplusflat.h

@@ -328,6 +328,7 @@ GpStatus WINGDIPAPI GdipGetImageHorizontalResolution(GpImage*,REAL*);
 GpStatus WINGDIPAPI GdipGetImageItemData(GpImage*,ImageItemData*);
 GpStatus WINGDIPAPI GdipGetImagePixelFormat(GpImage*,PixelFormat*);
 GpStatus WINGDIPAPI GdipGetImageRawFormat(GpImage*,GUID*);
+GpStatus WINGDIPAPI GdipGetImageThumbnail(GpImage*,UINT,UINT,GpImage**,GetThumbnailImageAbort,VOID*);
 GpStatus WINGDIPAPI GdipGetImageType(GpImage*,ImageType*);
 GpStatus WINGDIPAPI GdipGetImageVerticalResolution(GpImage*,REAL*);
 GpStatus WINGDIPAPI GdipGetImageWidth(GpImage*,UINT*);