Simplify view getters on GrTextureProducer.

The only thing that affects the view returned is whether it ought to
be MIP mapped or not. So don't take a whole GrSamplerState.

The view() function won't ever change the colortype so just query
GrTextureProducer rather than having view() return a tuple.

The rest is transitively reaching through callers and callees of
GrTextureProducer::view() to only pass filter or GrMipMapped instead of
GrSamplerState. Also, some params that indicate whether MIPs are
requested are changed from bool to GrMipMapped. And some minor style
stuff (mainly de-yoda-ifying GrMipMapped checks, using
GrSurfaceProxyView operator bool()).

Change-Id: Ia184aa793cf51d42642ea3bb0521ce06da2efb10
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/274205
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrBackendTextureImageGenerator.h b/src/gpu/GrBackendTextureImageGenerator.h
index cef161c..283fa39 100644
--- a/src/gpu/GrBackendTextureImageGenerator.h
+++ b/src/gpu/GrBackendTextureImageGenerator.h
@@ -39,8 +39,8 @@
     // do that safely (we might be on another thread). So assume everything is fine.
     bool onIsValid(GrContext*) const override { return true; }
 
-    GrSurfaceProxyView onGenerateTexture(GrRecordingContext*, const SkImageInfo&,
-                                         const SkIPoint&, bool willNeedMipMaps) override;
+    GrSurfaceProxyView onGenerateTexture(GrRecordingContext*, const SkImageInfo&, const SkIPoint&,
+                                         GrMipMapped mipMapped) override;
     bool onTexturesAreCacheable() const override { return false; }
 
 private: