make set3DMask virtual, so we can safely notify the shadercontext

gm/emboss.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm.h"
+#include "SkBlurMaskFilter.h"
+#include "SkCanvas.h"
+#include "SkColorFilter.h"
+
+#include "SkColorFilter.h"
+static SkBitmap make_bm() {
+    SkBitmap bm;
+    bm.allocN32Pixels(100, 100);
+
+    SkCanvas canvas(bm);
+    canvas.clear(0);
+    SkPaint paint;
+    paint.setAntiAlias(true);
+    canvas.drawCircle(50, 50, 50, paint);
+    return bm;
+}
+
+class EmbossGM : public skiagm::GM {
+public:
+    EmbossGM() {
+    }
+
+protected:
+    virtual SkString onShortName() SK_OVERRIDE {
+        return SkString("emboss");
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE {
+        return SkISize::Make(600, 120);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        SkPaint paint;
+        SkBitmap bm = make_bm();
+        canvas->drawBitmap(bm, 10, 10, &paint);
+
+        const SkScalar dir[] = { 1, 1, 1 };
+        paint.setMaskFilter(SkBlurMaskFilter::CreateEmboss(3, dir, 0.3f, 0.1f))->unref();
+        canvas->translate(bm.width() + SkIntToScalar(10), 0);
+        canvas->drawBitmap(bm, 10, 10, &paint);
+
+        // this combination of emboss+colorfilter used to crash -- so we exercise it to
+        // confirm that we have a fix.
+        paint.setColorFilter(SkColorFilter::CreateModeFilter(0xFFFF0000, SkXfermode::kSrcATop_Mode))->unref();
+        canvas->translate(bm.width() + SkIntToScalar(10), 0);
+        canvas->drawBitmap(bm, 10, 10, &paint);
+    }
+
+private:
+    typedef skiagm::GM INHERITED;
+};
+
+DEF_GM( return SkNEW(EmbossGM); )