Remove redundant tests to make DM a little faster

dm/DM.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "CrashHandler.h"
 #include "DMJsonWriter.h"
 #include "DMSrcSink.h"
@@ skipping 529 matching lines @@
         for (float scale : nativeScales) {
             for (CodecSrc::DstColorType colorType : colorTypes) {
                 for (SkAlphaType alphaType : alphaModes) {
                     // Only test kCroppedScanline_Mode when the alpha type is opaque.  The test is
                     // slow and won't be interestingly different with different alpha types.
                     if (CodecSrc::kCroppedScanline_Mode == mode &&
                             kOpaque_SkAlphaType != alphaType) {
                         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);
                 }
             }
         }
     }
 
     if (FLAGS_simpleCodec) {
         return;
     }
 
@@ skipping 10 matching lines @@
             subset = true;
             break;
         }
     }
 
     const int sampleSizes[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
 
     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) {
                     push_android_codec_src(path, AndroidCodecSrc::kDivisor_Mode, colorType,
                             alphaType, sampleSize);
                 }
             }
         }
     }
 
@@ skipping 828 matching lines @@
 #endif
 }
 } // namespace skiatest
 
 #if !defined(SK_BUILD_FOR_IOS)
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return dm_main();
 }
 #endif