diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/include/core/SkDrawLooper.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/include/core/SkDrawLooper.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,102 @@
+
+/*
+ * Copyright 2011 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef SkDrawLooper_DEFINED
+#define SkDrawLooper_DEFINED
+
+#include "SkFlattenable.h"
+
+class SkCanvas;
+class SkPaint;
+struct SkRect;
+class SkString;
+
+/** \class SkDrawLooper
+    Subclasses of SkDrawLooper can be attached to a SkPaint. Where they are,
+    and something is drawn to a canvas with that paint, the looper subclass will
+    be called, allowing it to modify the canvas and/or paint for that draw call.
+    More than that, via the next() method, the looper can modify the draw to be
+    invoked multiple times (hence the name loop-er), allow it to perform effects
+    like shadows or frame/fills, that require more than one pass.
+*/
+class SK_API SkDrawLooper : public SkFlattenable {
+public:
+    SK_DECLARE_INST_COUNT(SkDrawLooper)
+
+    /**
+     *  Holds state during a draw. Users call next() until it returns false.
+     *
+     *  Subclasses of SkDrawLooper should create a subclass of this object to
+     *  hold state specific to their subclass.
+     */
+    class SK_API Context : public SkNoncopyable {
+    public:
+        Context() {}
+        virtual ~Context() {}
+
+        /**
+         *  Called in a loop on objects returned by SkDrawLooper::createContext().
+         *  Each time true is returned, the object is drawn (possibly with a modified
+         *  canvas and/or paint). When false is finally returned, drawing for the object
+         *  stops.
+         *
+         *  On each call, the paint will be in its original state, but the
+         *  canvas will be as it was following the previous call to next() or
+         *  createContext().
+         *
+         *  The implementation must ensure that, when next() finally returns
+         *  false, the canvas has been restored to the state it was
+         *  initially, before createContext() was first called.
+         */
+        virtual bool next(SkCanvas* canvas, SkPaint* paint) = 0;
+    };
+
+    /**
+     *  Called right before something is being drawn. Returns a Context
+     *  whose next() method should be called until it returns false.
+     *  The caller has to ensure that the storage pointer provides enough
+     *  memory for the Context. The required size can be queried by calling
+     *  contextSize(). It is also the caller's responsibility to destroy the
+     *  object after use.
+     */
+    virtual Context* createContext(SkCanvas*, void* storage) const = 0;
+
+    /**
+      *  Returns the number of bytes needed to store subclasses of Context (belonging to the
+      *  corresponding SkDrawLooper subclass).
+      */
+    virtual size_t contextSize() const = 0;
+
+
+    /**
+     * The fast bounds functions are used to enable the paint to be culled early
+     * in the drawing pipeline. If a subclass can support this feature it must
+     * return true for the canComputeFastBounds() function.  If that function
+     * returns false then computeFastBounds behavior is undefined otherwise it
+     * is expected to have the following behavior. Given the parent paint and
+     * the parent's bounding rect the subclass must fill in and return the
+     * storage rect, where the storage rect is with the union of the src rect
+     * and the looper's bounding rect.
+     */
+    virtual bool canComputeFastBounds(const SkPaint& paint) const;
+    virtual void computeFastBounds(const SkPaint& paint,
+                                   const SkRect& src, SkRect* dst) const;
+
+    SK_TO_STRING_PUREVIRT()
+    SK_DEFINE_FLATTENABLE_TYPE(SkDrawLooper)
+
+protected:
+    SkDrawLooper() {}
+    SkDrawLooper(SkReadBuffer& buffer) : INHERITED(buffer) {}
+
+private:
+    typedef SkFlattenable INHERITED;
+};
+
+#endif