Migrate some last instances of GrContext to GrDirectContext

This is a rename with no functional changes.

Change-Id: I4b0b7ee1926b688029e257b35c469113c0404a5b
diff --git a/libs/hwui/pipeline/skia/ShaderCache.h b/libs/hwui/pipeline/skia/ShaderCache.h
index 5b8e668..4dcc9fb 100644
--- a/libs/hwui/pipeline/skia/ShaderCache.h
+++ b/libs/hwui/pipeline/skia/ShaderCache.h
@@ -80,7 +80,7 @@
      * Pipeline cache is saved on disk only if the size of the data has changed or there was
      * a new shader compiled.
      */
-    void onVkFrameFlushed(GrContext* context);
+    void onVkFrameFlushed(GrDirectContext* context);
 
 private:
     // Creation and (the lack of) destruction is handled internally.