SK_API in src/gpu cleanup

Change-Id: I14d6f7ef06c3cfcefd0813dd5013e4185b12d8cc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/235804
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrTextureContext.h b/src/gpu/GrTextureContext.h
index cf09283..ac9a43c 100644
--- a/src/gpu/GrTextureContext.h
+++ b/src/gpu/GrTextureContext.h
@@ -23,7 +23,7 @@
  * A helper object to orchestrate commands (currently just copies) for GrSurfaces that are
  * GrTextures and not GrRenderTargets.
  */
-class SK_API GrTextureContext : public GrSurfaceContext {
+class GrTextureContext : public GrSurfaceContext {
 public:
     ~GrTextureContext() override;