Add private save-behind and draw-behind methods to canvas.HEADp9.0

The draw-behind  is a variant of drawPaint but is automatically clipped
to the bounds of the most recent saveBehind buffer (axis-aligned bounds).

No public exposure outside of the Android framework.

Impl is pretty simple (its a variant of drawPaint)
- find the most recent saveBehind device bounds
- if there is none, draw nothing, else
  - temporarily intersect the device's clip with that bounds
  - drawPaint
  - restore the clip

This patches did not apply cleanly and have been updated to compile
with a previous version of Skia. It was cherry-picked from the
following 3 Skia commits:
148b7fd3ad9c29dec0052de624c26ff291ef8f0a
d567408362bf7847d6000f6786f9a7b2c9d0b88b
9adc82c73df0ef25b708cae8aa48ef9c39ed4c67

Bug: 129117085
Test: None
Change-Id: I291f57885de6e95f749bf5cdb70ac16a5781ffb1

4 files changed, 6 insertions, 0 deletions

diff --git a/include/utils/SkLuaCanvas.h b/include/utils/SkLuaCanvas.h
index 2fef2c0785..fc2e73d827 100644
--- a/include/utils/SkLuaCanvas.h
+++ b/include/utils/SkLuaCanvas.h
@@ -24,6 +24,7 @@ public:
 protected:
     void willSave() override;
     SaveLayerStrategy getSaveLayerStrategy(const SaveLayerRec&) override;
+    bool onDoSaveBehind(const SkRect*) override;
     void willRestore() override;
 
     void didConcat(const SkMatrix&) override;
diff --git a/include/utils/SkNWayCanvas.h b/include/utils/SkNWayCanvas.h
index a3e567ef89..57bd6de1eb 100644
--- a/include/utils/SkNWayCanvas.h
+++ b/include/utils/SkNWayCanvas.h
@@ -33,6 +33,7 @@ protected:
 
     void willSave() override;
     SaveLayerStrategy getSaveLayerStrategy(const SaveLayerRec&) override;
+    bool onDoSaveBehind(const SkRect*) override;
     void willRestore() override;
 
     void didConcat(const SkMatrix&) override;
@@ -56,6 +57,7 @@ protected:
                              const SkPaint& paint) override;
 
     void onDrawPaint(const SkPaint&) override;
+    void onDrawBehind(const SkPaint&) override;
     void onDrawPoints(PointMode, size_t count, const SkPoint pts[], const SkPaint&) override;
     void onDrawRect(const SkRect&, const SkPaint&) override;
     void onDrawOval(const SkRect&, const SkPaint&) override;
diff --git a/include/utils/SkNoDrawCanvas.h b/include/utils/SkNoDrawCanvas.h
index 7b3eaf6b18..65d7403194 100644
--- a/include/utils/SkNoDrawCanvas.h
+++ b/include/utils/SkNoDrawCanvas.h
@@ -35,6 +35,7 @@ public:
 
 protected:
     SaveLayerStrategy getSaveLayerStrategy(const SaveLayerRec& rec) override;
+    bool onDoSaveBehind(const SkRect*) override;
 
     // No-op overrides for aborting rasterization earlier than SkNullBlitter.
     void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&) override {}
@@ -51,6 +52,7 @@ protected:
                      const SkPaint&) override {}
 
     void onDrawPaint(const SkPaint&) override {}
+    void onDrawBehind(const SkPaint&) override {}
     void onDrawPoints(PointMode, size_t, const SkPoint[], const SkPaint&) override {}
     void onDrawRect(const SkRect&, const SkPaint&) override {}
     void onDrawRegion(const SkRegion&, const SkPaint&) override {}
diff --git a/include/utils/SkPaintFilterCanvas.h b/include/utils/SkPaintFilterCanvas.h
index d6689b91bc..4cf29dbd18 100644
--- a/include/utils/SkPaintFilterCanvas.h
+++ b/include/utils/SkPaintFilterCanvas.h
@@ -65,6 +65,7 @@ protected:
     virtual bool onFilter(SkTCopyOnFirstWrite<SkPaint>* paint, Type type) const = 0;
 
     void onDrawPaint(const SkPaint&) override;
+    void onDrawBehind(const SkPaint&) override;
     void onDrawPoints(PointMode, size_t count, const SkPoint pts[], const SkPaint&) override;
     void onDrawRect(const SkRect&, const SkPaint&) override;
     void onDrawRRect(const SkRRect&, const SkPaint&) override;