gpu: Expose GrContextPriv::abandoned in the public API.

TBR=bsalomon@google.com

Bug: 854416
Change-Id: Iab71ca6e4724a925b0b9791267aac5ddc34f5b15
Reviewed-on: https://skia-review.googlesource.com/137692
Reviewed-by: Khusal Sagar <khushalsagar@chromium.org>
Commit-Queue: Khusal Sagar <khushalsagar@chromium.org>
diff --git a/gm/rectangletexture.cpp b/gm/rectangletexture.cpp
index d6bf1fb..c22e420 100644
--- a/gm/rectangletexture.cpp
+++ b/gm/rectangletexture.cpp
@@ -60,7 +60,7 @@
         if (!context) {
             return nullptr;
         }
-        if (context->contextPriv().abandoned()) {
+        if (context->abandoned()) {
             return nullptr;
         }
         GrGpu* gpu = context->contextPriv().getGpu();