add saveBehind to canvas

Bug: skia:
Change-Id: I62e48b116b2d7efef585d4f465441f24ae4d2b29
Reviewed-on: https://skia-review.googlesource.com/c/177892
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/include/android/SkAndroidFrameworkUtils.h b/include/android/SkAndroidFrameworkUtils.h
index 9df1c84..67b8492 100644
--- a/include/android/SkAndroidFrameworkUtils.h
+++ b/include/android/SkAndroidFrameworkUtils.h
@@ -14,6 +14,7 @@
 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
 
 class SkCanvas;
+struct SkRect;
 class SkSurface;
 
 /**
@@ -37,6 +38,8 @@
     static void SafetyNetLog(const char*);
 
     static sk_sp<SkSurface> getSurfaceFromCanvas(SkCanvas* canvas);
+
+    static int SaveBehind(SkCanvas* canvas, const SkRect* subset);
 };
 
 #endif // SK_BUILD_FOR_ANDROID_ANDROID