Rename outputSwizzle->writeSwizzle.

It is also used for writes to surfaces other than fragment shader
output. e.g. clears.

Change-Id: Id1eb79be6d1a8aed936456bffa59dee32661cec8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/280344
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrSurfaceContext.cpp b/src/gpu/GrSurfaceContext.cpp
index 7e18008..4d1b23b 100644
--- a/src/gpu/GrSurfaceContext.cpp
+++ b/src/gpu/GrSurfaceContext.cpp
@@ -47,8 +47,8 @@
         SkASSERT(kPremul_SkAlphaType == alphaType || kOpaque_SkAlphaType == alphaType);
         // Will we ever want a swizzle that is not the default output swizzle for the format and
         // colorType here? If so we will need to manually pass that in.
-        GrSwizzle outSwizzle = context->priv().caps()->getOutputSwizzle(proxy->backendFormat(),
-                                                                        colorType);
+        GrSwizzle outSwizzle =
+                context->priv().caps()->getWriteSwizzle(proxy->backendFormat(), colorType);
         GrSurfaceProxyView outputView(readView.refProxy(), readView.origin(), outSwizzle);
         surfaceContext.reset(new GrRenderTargetContext(context, std::move(readView),
                                                        std::move(outputView), colorType,