Make SkAndroidCodec support wbmp

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 326 matching lines @@
     }
 
     for (float scale : nativeScales) {
         for (CodecSrc::Mode mode : nativeModes) {
             for (uint32_t i = 0; i < numColorTypes; i++) {
                 push_codec_src(path, mode, colorTypes[i], scale);
             }
         }
     }
 
+    uint32_t numAndroidModes = 0;
     // https://bug.skia.org/4428
+    // Only test subsets for these selected image types.

[scroggo, 2015/11/16 15:19:58]

nit: This sentence is ambiguous - I read it as meaning that for these image
types, we test subsets, but not full decodes.

     static const char* const exts[] = {
         "jpg", "jpeg", "png", "webp",
         "JPG", "JPEG", "PNG", "WEBP",
     };
-    bool supported = false;
     for (const char* ext : exts) {
         if (path.endsWith(ext)) {
-            supported = true;
+            numAndroidModes = 2;
             break;
         }
     }
-    if (!supported) {
-        return;
+
+    static const char* onlyFullImageExts[] = {
+        "wbmp",
+        "WBMP",
+    };
+    for (const char* ext : onlyFullImageExts) {
+        if (path.endsWith(ext)) {
+            numAndroidModes = 1;
+            break;
+        }
     }
 
     const int sampleSizes[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
 
     const AndroidCodecSrc::Mode androidModes[] = {
             AndroidCodecSrc::kFullImage_Mode,
             AndroidCodecSrc::kDivisor_Mode,
     };
 
     for (int sampleSize : sampleSizes) {
-        for (AndroidCodecSrc::Mode mode : androidModes) {
+        for (uint32_t m = 0; m < numAndroidModes; m++) {

[scroggo, 2015/11/16 15:19:58]

Now I think I see why you were tempted to go all the way and turn on subset
decoding - this is messy...

Two thoughts:
1. Testing subsets using SkAndroidCodec is pretty similar to using the BRD test
(which in turn uses SkAndroidCodec). Is there a benefit to having both? Or could
we cut down the androidModes to just kFullImage?
2. If we see value in having both versions of subset tests, do you think the
following is more clear?

// set new booleans "full" and "subset" how you currently set numAndroidModes,
// or possibly use static functions.

if (!full && !subset) {
  return;
}

for (sampleSize : sampleSizes) {
  for (colorType : colorTypes) {
    push_android_codec_src(path, kFullImage, colorType, sampleSize);
    if (subset) {
      push_android_codec_src(path, kDivisor, colorType, sampleSize);
    }
  }
} 

[msarett, 2015/11/16 15:40:57]

I think you could make a good argument for this.  Right now, I'm not sure there
is much benefit to having both tests.  I'm hesitating on deleting this test
because I'm wondering if we might ever want subsets without a
BitmapRegionDecoder.
Yeah I like this better.

             for (uint32_t i = 0; i < numColorTypes; i++) {
-                push_android_codec_src(path, mode, colorTypes[i], sampleSize);
+                push_android_codec_src(path, androidModes[m], colorTypes[i], sampleSize);
             }
         }
     }
 }
 
 static bool brd_color_type_supported(SkBitmapRegionDecoder::Strategy strategy,
         CodecSrc::DstColorType dstColorType) {
     switch (strategy) {
         case SkBitmapRegionDecoder::kCanvas_Strategy:
             if (CodecSrc::kGetFromCanvas_DstColorType == dstColorType) {
@@ skipping 747 matching lines @@
     #endif  // SK_PDF_IMAGE_STATS
     return 0;
 }
 
 #if !defined(SK_BUILD_FOR_IOS)
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return dm_main();
 }
 #endif