Only decode opaque to premul in DM image

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 355 matching lines @@
             folder.append("_kIndex8");
             break;
         case CodecSrc::kNonNative8888_Always_DstColorType:
             folder.append("_kNonNative");
             break;
         default:
             break;
     }
 
     switch (dstAlphaType) {
-        case kOpaque_SkAlphaType:
-            folder.append("_opaque");
-            break;
         case kPremul_SkAlphaType:
             folder.append("_premul");
             break;
         case kUnpremul_SkAlphaType:
             folder.append("_unpremul");
             break;
         default:
             break;
     }
 
@@ skipping 18 matching lines @@
             folder.append("_kIndex8");
             break;
         case CodecSrc::kNonNative8888_Always_DstColorType:
             folder.append("_kNonNative");
             break;
         default:
             break;
     }
 
     switch (dstAlphaType) {
-        case kOpaque_SkAlphaType:
-            folder.append("_opaque");
-            break;
         case kPremul_SkAlphaType:
             folder.append("_premul");
             break;
         case kUnpremul_SkAlphaType:
             folder.append("_unpremul");
             break;
         default:
             break;
     }
 
@@ skipping 87 matching lines @@
             break;
         case kIndex_8_SkColorType:
             colorTypes.push_back(CodecSrc::kIndex8_Always_DstColorType);
             break;
         default:
             break;
     }
 
     SkTArray<SkAlphaType> alphaModes;
     alphaModes.push_back(kPremul_SkAlphaType);
-    alphaModes.push_back(kUnpremul_SkAlphaType);
-    if (codec->getInfo().alphaType() == kOpaque_SkAlphaType) {
-        alphaModes.push_back(kOpaque_SkAlphaType);
+    if (codec->getInfo().alphaType() != kOpaque_SkAlphaType) {
+        alphaModes.push_back(kUnpremul_SkAlphaType);
     }
 
     for (CodecSrc::Mode mode : nativeModes) {
         for (CodecSrc::DstColorType colorType : colorTypes) {
             for (SkAlphaType alphaType : alphaModes) {
-                // Only test kCroppedScanline_Mode when the alpha type is opaque.  The test is
+                // Only test kCroppedScanline_Mode when the alpha type is premul.  The test is
                 // slow and won't be interestingly different with different alpha types.
                 if (CodecSrc::kCroppedScanline_Mode == mode &&
-                        kOpaque_SkAlphaType != alphaType) {
+                        kPremul_SkAlphaType != alphaType) {
                     continue;
                 }
 
                 push_codec_src(path, mode, colorType, alphaType, 1.0f);
 
                 // Skip kNonNative on different native scales.  It won't be interestingly
                 // different.
                 if (supportsNativeScaling &&
                         CodecSrc::kNonNative8888_Always_DstColorType == colorType) {
                     // Native Scales
@@ skipping 831 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