skip call to clip::apply when clip is wide open

src/gpu/GrClipStackClip.h

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrClipStackClip_DEFINED
+#define GrClipStackClip_DEFINED
+
+#include "GrClip.h"
+#include "GrReducedClip.h"
+#include "GrTypesPriv.h"
+#include "SkClipStack.h"
+
+class GrDrawContext;
+class GrPathRenderer;
+
+/**
+ * GrClipStackClip can apply a generic SkClipStack to the draw state. It may generate clip masks or
+ * write to the stencil buffer during apply().
+ */
+class GrClipStackClip final : public GrClip {
+public:
+    GrClipStackClip(const SkClipStack* stack = nullptr, const SkIPoint* origin = nullptr)
+            : INHERITED(!stack || stack->isWideOpen()) {
+        this->reset(stack, origin);
+    }
+
+    void reset(const SkClipStack* stack = nullptr, const SkIPoint* origin = nullptr) {
+        fIsWideOpen = !stack || stack->isWideOpen();
+        fOrigin = origin ? *origin : SkIPoint::Make(0, 0);
+        fStack.reset(SkSafeRef(stack));
+    }
+
+    const SkIPoint& origin() const { return fOrigin; }
+    const SkClipStack* clipStack() const { return fStack; }
+
+    bool quickContains(const SkRect&) const final;
+    void getConservativeBounds(int width, int height, SkIRect* devResult,
+                               bool* isIntersectionOfRects) const final;
+    bool apply(GrContext*, const GrPipelineBuilder&, GrDrawContext*,
+               const SkRect* devBounds, GrAppliedClip*) const final;
+
+private:
+    static bool UseSWOnlyPath(GrContext* context,
+                              const GrPipelineBuilder& pipelineBuilder,
+                              const GrDrawContext* drawContext,
+                              const SkVector& clipToMaskOffset,
+                              const GrReducedClip::ElementList& elements);
+    static bool PathNeedsSWRenderer(GrContext* context, bool hasUserStencilSettings,
+                                    const GrDrawContext*, const SkMatrix& viewMatrix,
+                                    const SkClipStack::Element* element, GrPathRenderer** prOut,
+                                    bool needsStencil);
+    static bool CreateStencilClipMask(GrContext* context,
+                                      GrDrawContext* drawContext,
+                                      int32_t elementsGenID,
+                                      GrReducedClip::InitialState initialState,
+                                      const GrReducedClip::ElementList& elements,
+                                      const SkIRect& clipSpaceIBounds,
+                                      const SkIPoint& clipSpaceToStencilOffset);
+
+    SkIPoint                          fOrigin;
+    SkAutoTUnref<const SkClipStack>   fStack;
+    typedef GrClip INHERITED;
+};
+
+#endif