Simplify common case of linear filtering with no mips

Change-Id: I08b4a7bc088705b93a0aa680f6733d09c7ad23dd
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/354221
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index 7598c22..1b4e096 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -698,8 +698,7 @@
 
     auto gamutImage = GetResourceAsImage("images/gamut.png");
     if (gamutImage) {
-        fImGuiGamutPaint.setShader(gamutImage->makeShader(SkSamplingOptions(SkFilterMode::kLinear,
-                                                                            SkMipmapMode::kNone)));
+        fImGuiGamutPaint.setShader(gamutImage->makeShader(SkSamplingOptions(SkFilterMode::kLinear)));
     }
     fImGuiGamutPaint.setColor(SK_ColorWHITE);