Implement a resize image filter. This is needed for the "filterRes" feature in SVG filter effects, …

include/effects/SkResizeImageFilter.h

+/*
+ * Copyright 2013 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkResizeImageFilter_DEFINED
+#define SkResizeImageFilter_DEFINED
+
+#include "SkImageFilter.h"
+#include "SkScalar.h"
+#include "SkRect.h"
+#include "SkPoint.h"
+#include "SkPaint.h"
+
+/*! \class SkResizeImageFilter
+    Resampling image filter. This filter draws its source image resampled using the given scale
+    values.
+ */
+
+class SK_API SkResizeImageFilter : public SkImageFilter {
+public:
+    /** Construct a (scaling-only) resampling image filter.
+     *  @param sx           The x scale parameter to apply when resizing.
+     *  @param sy           The y scale parameter to apply when resizing.
+     *  @param filterLevel  The quality of filtering to apply when scaling.
+     *  @param input        The input image filter.  If NULL, the src bitmap
+     *                      passed to filterImage() is used instead.
+     */
+
+    SkResizeImageFilter(SkScalar sx, SkScalar sy, SkPaint::FilterLevel filterLevel,
+                        SkImageFilter* input = NULL);
+    virtual ~SkResizeImageFilter();
+
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkResizeImageFilter)
+
+protected:
+    SkResizeImageFilter(SkFlattenableReadBuffer& buffer);
+    virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
+
+    virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
+                               SkBitmap* result, SkIPoint* loc) SK_OVERRIDE;
+
+private:
+    SkScalar              fSx, fSy;
+    SkPaint::FilterLevel  fFilterLevel;
+    typedef SkImageFilter INHERITED;
+};
+
+#endif