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, 19 insertions, 0 deletions

diff --git a/src/core/SkSpecialImage.cpp b/src/core/SkSpecialImage.cpp
index 61acd3fc69..679c09464f 100644
--- a/src/core/SkSpecialImage.cpp
+++ b/src/core/SkSpecialImage.cpp
@@ -337,6 +337,25 @@ sk_sp<SkSpecialImage> SkSpecialImage::MakeFromRaster(const SkIRect& subset,
     return sk_make_sp<SkSpecialImage_Raster>(subset, *srcBM, props);
 }
 
+sk_sp<SkSpecialImage> SkSpecialImage::CopyFromRaster(const SkIRect& subset,
+                                                     const SkBitmap& bm,
+                                                     const SkSurfaceProps* props) {
+    SkASSERT(rect_fits(subset, bm.width(), bm.height()));
+
+    if (!bm.pixelRef()) {
+        return nullptr;
+    }
+
+    SkBitmap tmp;
+    if (!tmp.tryAllocPixels(bm.info().makeWH(subset.width(), subset.height()))) {
+        return nullptr;
+    }
+    if (!bm.readPixels(tmp.info(), tmp.getPixels(), tmp.rowBytes(), subset.x(), subset.y())) {
+        return nullptr;
+    }
+    return sk_make_sp<SkSpecialImage_Raster>(subset, tmp, props);
+}
+
 #if SK_SUPPORT_GPU
 ///////////////////////////////////////////////////////////////////////////////
 static sk_sp<SkImage> wrap_proxy_in_image(GrContext* context, sk_sp<GrTextureProxy> proxy,