Restore GrRenderTargetContext as an alias for GrSurfaceDrawContext

Android framework is relying on the old header and old name.

Change-Id: I64065027bb7e96e47bc38b9df973383e236161ab
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/343103
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Stan Iliev <stani@google.com>
Commit-Queue: Stan Iliev <stani@google.com>

src/gpu/GrRenderTargetContext.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrRenderTargetContext_DEFINED
+#define GrRenderTargetContext_DEFINED
+
+#include "include/core/SkTypes.h"
+
+#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
+
+#include "src/gpu/GrSurfaceDrawContext.h"
+
+// Android Framework is relying on this header existing and the old name
+// of GrSurfaceDrawContext.
+
+using GrRenderTargetContext = GrSurfaceDrawContext;
+
+#endif
+
+#endif