Downgrade GpuGMs to only receiving a GrRecordingContext

Most of this CL is just noise (i.e., all the header changes) due to the
signature change. The 'discard' GM has some substantive changes but
that's about it.

Change-Id: I72011a442c149b5db93cf8decade6779be4f63d8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/296704
Reviewed-by: Adlai Holler <adlai@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/gm/tessellation.cpp b/gm/tessellation.cpp
index bb92397..ab9ceea 100644
--- a/gm/tessellation.cpp
+++ b/gm/tessellation.cpp
@@ -49,7 +49,7 @@
 class TessellationGM : public GpuGM {
     SkString onShortName() override { return SkString("tessellation"); }
     SkISize onISize() override { return {kWidth, kHeight}; }
-    DrawResult onDraw(GrContext*, GrRenderTargetContext*, SkCanvas*, SkString*) override;
+    DrawResult onDraw(GrRecordingContext*, GrRenderTargetContext*, SkCanvas*, SkString*) override;
 };
 
 
@@ -378,8 +378,8 @@
     return outset;
 }
 
-DrawResult TessellationGM::onDraw(GrContext* ctx, GrRenderTargetContext* rtc, SkCanvas* canvas,
-                                  SkString* errorMsg) {
+DrawResult TessellationGM::onDraw(GrRecordingContext* ctx, GrRenderTargetContext* rtc,
+                                  SkCanvas* canvas, SkString* errorMsg) {
     if (!ctx->priv().caps()->shaderCaps()->tessellationSupport()) {
         *errorMsg = "Requires GPU tessellation support.";
         return DrawResult::kSkip;