Move SkNoSaveLayerCanvas.h to include/utils

https://codereview.chromium.org/197243005



git-svn-id: http://skia.googlecode.com/svn/trunk@13823 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/utils/SkNoSaveLayerCanvas.h b/include/utils/SkNoSaveLayerCanvas.h
new file mode 100644
index 0000000..686f179
--- /dev/null
+++ b/include/utils/SkNoSaveLayerCanvas.h
@@ -0,0 +1,47 @@
+/*
+ * 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 SkNoSaveLayerCanvas_DEFINED
+#define SkNoSaveLayerCanvas_DEFINED
+
+#include "SkCanvas.h"
+#include "SkRRect.h"
+
+// The NoSaveLayerCanvas is used to play back SkPictures when the saveLayer
+// functionality isn't required (e.g., during analysis of the draw calls).
+// It also simplifies the clipping calls to only use rectangles.
+class SK_API SkNoSaveLayerCanvas : public SkCanvas {
+public:
+    SkNoSaveLayerCanvas(SkBaseDevice* device) : INHERITED(device) {}
+
+protected:
+    virtual SaveLayerStrategy willSaveLayer(const SkRect* bounds, const SkPaint* paint,
+                                            SaveFlags flags) SK_OVERRIDE {
+        this->INHERITED::willSaveLayer(bounds, paint, flags);
+        return kNoLayer_SaveLayerStrategy;
+    }
+
+    // disable aa for speed
+    virtual void onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle) SK_OVERRIDE {
+        this->INHERITED::onClipRect(rect, op, kHard_ClipEdgeStyle);
+    }
+
+    // for speed, just respect the bounds, and disable AA. May give us a few
+    // false positives and negatives.
+    virtual void onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle) SK_OVERRIDE {
+        this->updateClipConservativelyUsingBounds(path.getBounds(), op,
+                                                  path.isInverseFillType());
+    }
+    virtual void onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle) SK_OVERRIDE {
+        this->updateClipConservativelyUsingBounds(rrect.getBounds(), op, false);
+    }
+
+private:
+    typedef SkCanvas INHERITED;
+};
+
+#endif // SkNoSaveLayerCanvas_DEFINED