Make asDirectContext return a GrDirectContext

Change-Id: I373658d68582adc9728f3a75d84178a365f5b798
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/299877
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Adlai Holler <adlai@google.com>
diff --git a/src/gpu/GrRenderTargetContext.cpp b/src/gpu/GrRenderTargetContext.cpp
index e5c7bac..bf6906f 100644
--- a/src/gpu/GrRenderTargetContext.cpp
+++ b/src/gpu/GrRenderTargetContext.cpp
@@ -10,6 +10,7 @@
 #include "include/core/SkDrawable.h"
 #include "include/core/SkVertices.h"
 #include "include/gpu/GrBackendSemaphore.h"
+#include "include/private/GrDirectContext.h"
 #include "include/private/GrImageContext.h"
 #include "include/private/GrRecordingContext.h"
 #include "include/private/SkShadowFlags.h"