Add GM to repro crbug.com/472795

gm/bitmapsource2.cpp

Index: gm/bitmapsource2.cpp
diff --git a/gm/bitmapsource2.cpp b/gm/bitmapsource2.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..bc4acf717c3150d9cb5ac7ef2f34b408986a88c9
--- /dev/null
+++ b/gm/bitmapsource2.cpp
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2015 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 "SkBitmapSource.h"
+
+namespace skiagm {
+
+// This GM reproduces the issue in crbug.com/472795. The SkBitmapSource image
+// is shifted for high quality mode between cpu and gpu.
+class BitmapSourceGM : public GM {
+public:
+    BitmapSourceGM(const char* suffix, SkFilterQuality filter) : fSuffix(suffix), fFilter(filter) {
+        this->setBGColor(0xFFFFFFFF);
+    }
+
+protected:
+    SkString onShortName() override {
+        SkString name("bitmapsrc2_");
+        name.append(fSuffix);
+        return name;
+    }
+
+    SkISize onISize() override { return SkISize::Make(256, 256); }
+
+    // Create a bitmap with high frequency vertical stripes
+    void onOnceBeforeDraw() override {
+        static const SkPMColor gColors[] = {
+            SK_ColorRED,     SK_ColorGRAY,
+            SK_ColorGREEN,   SK_ColorGRAY,
+            SK_ColorBLUE,    SK_ColorGRAY,
+            SK_ColorCYAN,    SK_ColorGRAY,
+            SK_ColorMAGENTA, SK_ColorGRAY,
+            SK_ColorYELLOW,  SK_ColorGRAY,
+            SK_ColorWHITE,   SK_ColorGRAY,
+        };
+
+        fBM.allocN32Pixels(kImageSize, kImageSize, true);
+
+        SkCanvas canvas(fBM);
+
+        int curColor = 0;
+
+        for (int x = 0; x < kImageSize; x += 3) {
+            SkRect r = SkRect::MakeXYWH(SkIntToScalar(x), SkIntToScalar(0), 
+                                        SkIntToScalar(3), SkIntToScalar(kImageSize));
+            SkPaint p;
+            p.setColor(gColors[curColor]);
+            canvas.drawRect(r, p);
+
+            curColor = (curColor+1) % SK_ARRAY_COUNT(gColors);
+        }
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        SkRect srcRect = SkRect::MakeLTRB(0, 0,
+                                          SkIntToScalar(kImageSize), SkIntToScalar(kImageSize));
+        SkRect dstRect = SkRect::MakeLTRB(0.75f, 0.75f, 225.75f, 225.75f);
+
+        SkAutoTUnref<SkImageFilter> filter(SkBitmapSource::Create(fBM, srcRect, dstRect, fFilter));
+
+        SkPaint p;
+        p.setImageFilter(filter);
+
+        canvas->saveLayer(NULL, &p);
+        canvas->restore();
+    }
+
+private:
+    static const int kImageSize = 503;
+
+    SkString fSuffix;
+    SkFilterQuality fFilter;
+    SkBitmap fBM;
+
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return SkNEW_ARGS(BitmapSourceGM, ("none", kNone_SkFilterQuality) );   )
+DEF_GM( return SkNEW_ARGS(BitmapSourceGM, ("low",  kLow_SkFilterQuality) );    )
+DEF_GM( return SkNEW_ARGS(BitmapSourceGM, ("med",  kMedium_SkFilterQuality) ); )
+DEF_GM( return SkNEW_ARGS(BitmapSourceGM, ("high", kHigh_SkFilterQuality) );   )
+
+}