Switch from querying swizzle on caps to using swizzles stored on proxies.

Change-Id: I03f4a3affd6dda7a83bee8eec768dcaa93a6b801
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/220534
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
diff --git a/src/gpu/GrFragmentProcessor.h b/src/gpu/GrFragmentProcessor.h
index 44004c0..5789a1e 100644
--- a/src/gpu/GrFragmentProcessor.h
+++ b/src/gpu/GrFragmentProcessor.h
@@ -448,6 +448,7 @@
 
     GrTextureProxy* proxy() const { return fProxy.get(); }
     const GrSamplerState& samplerState() const { return fSamplerState; }
+    const GrSwizzle& swizzle() const { return this->proxy()->textureSwizzle(); }
 
     bool isInitialized() const { return SkToBool(fProxy.get()); }