Split SkPictureRangePlayback out of SkPicturePlayback

src/core/SkPictureRangePlayback.h

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkPictureRangePlayback_DEFINED
+#define SkPictureRangePlayback_DEFINED
+
+#include "SkPicturePlayback.h"
+
+// This version of picture playback plays all the operations between
+// a pair of start and stop values.
+// The opcode at 'start' should be a saveLayer while the opcode at
+// 'stop' should be a restore. Neither of those commands will be issued.
+// Since this class never uses the bounding box hierarchy, the base class'
+// useBBH setting is ignored.
+class SkPictureRangePlayback : public SkPicturePlayback {
+public:
+    // Set both start & stop to 0 to disable draw limiting. Note that disabling
+    // draw limiting isn't the same as using the base SkPicturePlayback object
+    // since this class never uses the bounding box hierarchy information.
+    SkPictureRangePlayback(const SkPicture* picture, size_t start, size_t stop)
+    : INHERITED(picture)
+    , fStart(start)
+    , fStop(stop) {
+    }
+
+    virtual void draw(SkCanvas* canvas, SkDrawPictureCallback*) SK_OVERRIDE;
+
+private:
+    size_t fStart;
+    size_t fStop;
+
+    typedef SkPicturePlayback INHERITED;
+};
+
+
+#endif