Remove redundant tests to make DM a little faster

This should help with some of the slow down caused by
https://codereview.chromium.org/1907593004.

BUG=skia:5181
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1923533002

Review URL: https://codereview.chromium.org/1923533002
diff --git a/dm/DM.cpp b/dm/DM.cpp
index e77c99c..586a4e7 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -547,6 +547,13 @@
                         continue;
                     }
 
+                    // Skip kNonNative on different native scales.  It won't be interestingly
+                    // different.
+                    if (CodecSrc::kNonNative8888_Always_DstColorType == colorType && 1.0f != scale)
+                    {
+                        continue;
+                    }
+
                     push_codec_src(path, mode, colorType, alphaType, scale);
                 }
             }
@@ -577,6 +584,12 @@
     for (int sampleSize : sampleSizes) {
         for (CodecSrc::DstColorType colorType : colorTypes) {
             for (SkAlphaType alphaType : alphaModes) {
+                // We can exercise all of the kNonNative support code in the swizzler with just a
+                // few sample sizes.  Skip the rest.
+                if (CodecSrc::kNonNative8888_Always_DstColorType == colorType && sampleSize > 3) {
+                    continue;
+                }
+
                 push_android_codec_src(path, AndroidCodecSrc::kFullImage_Mode, colorType,
                         alphaType, sampleSize);
                 if (subset) {