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, 2 insertions, 1 deletions

diff --git a/include/core/SkPicture.h b/include/core/SkPicture.h
index b2beb56b86..9452feeda9 100644
--- a/include/core/SkPicture.h
+++ b/include/core/SkPicture.h
@@ -168,10 +168,11 @@ private:
     // V59: No more LocalSpace option on PictureImageFilter
     // V60: Remove flags in picture header
     // V61: Change SkDrawPictureRec to take two colors rather than two alphas
+    // V62: Add saveBehind
 
     // Only SKPs within the min/current picture version range (inclusive) can be read.
     static const uint32_t     MIN_PICTURE_VERSION = 56;     // august 2017
-    static const uint32_t CURRENT_PICTURE_VERSION = 61;
+    static const uint32_t CURRENT_PICTURE_VERSION = 62;
 
     static bool IsValidPictInfo(const SkPictInfo& info);
     static sk_sp<SkPicture> Forwardport(const SkPictInfo&,