Pull in Chromium's version of GatherPixelRefs

src/utils/SkGatherPixelRefsAndRects.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 "SkGatherPixelRefsAndRects.h"
+#include "SkNoSaveLayerCanvas.h"
+#include "SkPictureUtils.h"
+
+void SkPictureUtils::GatherPixelRefsAndRects(SkPicture* pict,
+                                             SkPictureUtils::SkPixelRefContainer* prCont) {
+    if (0 == pict->width() || 0 == pict->height()) {
+        return ;
+    }
+
+    SkGatherPixelRefsAndRectsDevice device(pict->width(), pict->height(), prCont);
+    SkNoSaveLayerCanvas canvas(&device);
+
+    canvas.clipRect(SkRect::MakeWH(SkIntToScalar(pict->width()), 
+                                   SkIntToScalar(pict->height())),
+                    SkRegion::kIntersect_Op, false);
+    canvas.drawPicture(*pict);
+}