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

1 files changed, 12 insertions, 0 deletions

diff --git a/src/core/SkRecordDraw.cpp b/src/core/SkRecordDraw.cpp
index 89eb8a751a..2d819e6799 100644
--- a/src/core/SkRecordDraw.cpp
+++ b/src/core/SkRecordDraw.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "SkRecordDraw.h"
+#include "SkCanvasPriv.h"
 #include "SkImage.h"
 #include "SkPatchUtils.h"
 
@@ -82,6 +83,15 @@ DRAW(SaveLayer, saveLayer(SkCanvas::SaveLayerRec(r.bounds,
                                                  r.clipMask.get(),
                                                  r.clipMatrix,
                                                  r.saveLayerFlags)));
+
+template <> void Draw::draw(const SaveBehind& r) {
+    SkCanvasPriv::SaveBehind(fCanvas, r.subset);
+}
+
+template <> void Draw::draw(const DrawBehind& r) {
+    SkCanvasPriv::DrawBehind(fCanvas, r.paint);
+}
+
 DRAW(SetMatrix, setMatrix(SkMatrix::Concat(fInitialCTM, r.matrix)));
 DRAW(Concat, concat(r.matrix));
 DRAW(Translate, translate(r.dx, r.dy));
@@ -290,6 +300,7 @@ private:
     // from the bounds of the ops in the same Save block.
     void trackBounds(const Save&)          { this->pushSaveBlock(nullptr); }
     void trackBounds(const SaveLayer& op)  { this->pushSaveBlock(op.paint); }
+    void trackBounds(const SaveBehind&)    { this->pushSaveBlock(nullptr); }
     void trackBounds(const Restore&) { fBounds[fCurrentOp] = this->popSaveBlock(); }
 
     void trackBounds(const SetMatrix&)         { this->pushControl(); }
@@ -396,6 +407,7 @@ private:
     Bounds bounds(const DrawText&) const { return fCurrentClipBounds; }
 
     Bounds bounds(const DrawPaint&) const { return fCurrentClipBounds; }
+    Bounds bounds(const DrawBehind&) const { return fCurrentClipBounds; }
     Bounds bounds(const NoOp&)  const { return Bounds::MakeEmpty(); }    // NoOps don't draw.
 
     Bounds bounds(const DrawRect& op) const { return this->adjustAndMap(op.rect, &op.paint); }