Remove SK_SUPPORT_LEGACY_BITMAP_FILTER guard

TBR=reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1695443002

Review URL: https://codereview.chromium.org/1695443002

src/core/SkBitmapController.cpp

@@ -105,12 +105,10 @@ bool SkDefaultBitmapControllerState::processHQRequest(const SkBitmapProvider& pr
         return false; // no need for HQ
     }
 
-#ifndef SK_SUPPORT_LEGACY_HQ_DOWNSAMPLING
     if (invScaleX > 1 || invScaleY > 1) {
         return false; // only use HQ when upsampling
     }
-#endif
-    
+
     const int dstW = SkScalarRoundToScalar(provider.width() / invScaleX);
     const int dstH = SkScalarRoundToScalar(provider.height() / invScaleY);
     const SkBitmapCacheDesc desc = provider.makeCacheDesc(dstW, dstH);