diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/gpu/GrReducedClip.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/gpu/GrReducedClip.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,43 @@
+
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkClipStack.h"
+#include "SkTLList.h"
+
+namespace GrReducedClip {
+
+typedef SkTLList<SkClipStack::Element> ElementList;
+
+enum InitialState {
+    kAllIn_InitialState,
+    kAllOut_InitialState,
+};
+
+/**
+ * This function takes a clip stack and a query rectangle and it produces a reduced set of
+ * SkClipStack::Elements that are equivalent to applying the full stack to the rectangle. The clip
+ * stack generation id that represents the list of elements is returned in resultGenID. The
+ * initial state of the query rectangle before the first clip element is applied is returned via
+ * initialState. Optionally, the caller can request a tighter bounds on the clip be returned via
+ * tighterBounds. If not NULL, tighterBounds will always be contained by queryBounds after return.
+ * If tighterBounds is specified then it is assumed that the caller will implicitly clip against it.
+ * If the caller specifies non-NULL for requiresAA then it will indicate whether anti-aliasing is
+ * required to process any of the elements in the result.
+ *
+ * This may become a member function of SkClipStack when its interface is determined to be stable.
+ * Marked SK_API so that SkLua can call this in a shared library build.
+ */
+SK_API void ReduceClipStack(const SkClipStack& stack,
+                            const SkIRect& queryBounds,
+                            ElementList* result,
+                            int32_t* resultGenID,
+                            InitialState* initialState,
+                            SkIRect* tighterBounds = NULL,
+                            bool* requiresAA = NULL);
+
+} // namespace GrReducedClip