Plumb GrColorType through all ops/processors that sample textures.

This change also allows for the remove of GrPixelConfigIsOpaque function.

Bug: skia:6718
Change-Id: I7e7b70f02d911eda67640d648fb6348091e0f55d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/248698
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
diff --git a/src/gpu/SkGr.cpp b/src/gpu/SkGr.cpp
index 52adfac..bdb3c3c 100644
--- a/src/gpu/SkGr.cpp
+++ b/src/gpu/SkGr.cpp
@@ -125,14 +125,15 @@
 }
 
 sk_sp<GrTextureProxy> GrCopyBaseMipMapToTextureProxy(GrRecordingContext* ctx,
-                                                     GrTextureProxy* baseProxy) {
+                                                     GrTextureProxy* baseProxy,
+                                                     GrColorType srcColorType) {
     SkASSERT(baseProxy);
 
     if (!ctx->priv().caps()->isFormatCopyable(baseProxy->backendFormat())) {
         return nullptr;
     }
-    return GrSurfaceProxy::Copy(ctx, baseProxy, GrMipMapped::kYes, SkBackingFit::kExact,
-                                SkBudgeted::kYes);
+    return GrSurfaceProxy::Copy(ctx, baseProxy, srcColorType, GrMipMapped::kYes,
+                                SkBackingFit::kExact, SkBudgeted::kYes);
 }
 
 sk_sp<GrTextureProxy> GrRefCachedBitmapTextureProxy(GrRecordingContext* ctx,