Add a SkPixelSerializer SkImage encode variant

tests/ImageTest.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkDevice.h"
 #include "SkImageEncoder.h"
 #include "SkImage_Base.h"
+#include "SkPixelSerializer.h"
 #include "SkRRect.h"
 #include "SkSurface.h"
 #include "SkUtils.h"
 #include "Test.h"
 
 #if SK_SUPPORT_GPU
 #include "GrContextFactory.h"
 #include "GrTest.h"
 #include "gl/GrGLInterface.h"
 #include "gl/GrGLUtil.h"
@@ skipping 74 matching lines @@
 DEF_GPUTEST(Image_Encode_Gpu, reporter, factory) {
     GrContext* ctx = factory->get(GrContextFactory::kNative_GLContextType);
     if (!ctx) {
         REPORTER_ASSERT(reporter, false);
         return;
     }
     test_encode(reporter, ctx);
 }
 #endif
 
+namespace {
+
+const char* kSerializedData = "serialized";
+
+class MockSerializer : public SkPixelSerializer {
+protected:
+    bool onUseEncodedData(const void*, size_t) override {
+        return false;
+    }
+
+    SkData* onEncodePixels(const SkImageInfo&, const void*, size_t) override {
+        return SkData::NewWithCString(kSerializedData);
+    }
+};
+
+} // anonymous namespace
+
+// Test that SkImage encoding observes custom pixel serializers.
+DEF_TEST(Image_Encode_Serializer, reporter) {
+    MockSerializer serializer;
+    const SkIRect ir = SkIRect::MakeXYWH(5, 5, 10, 10);
+    SkAutoTUnref<SkImage> image(make_image(nullptr, 20, 20, ir));
+    SkAutoTUnref<SkData> encoded(image->encode(&serializer));
+    SkAutoTUnref<SkData> reference(SkData::NewWithCString(kSerializedData));
+
+    REPORTER_ASSERT(reporter, encoded);
+    REPORTER_ASSERT(reporter, encoded->size() > 0);
+    REPORTER_ASSERT(reporter, encoded->equals(reference));
+}
+
 DEF_TEST(Image_NewRasterCopy, reporter) {
     const SkPMColor red =   SkPackARGB32(0xFF, 0xFF, 0, 0);
     const SkPMColor green = SkPackARGB32(0xFF, 0, 0xFF, 0);
     const SkPMColor blue =  SkPackARGB32(0xFF, 0, 0, 0xFF);
     SkPMColor colors[] = { red, green, blue, 0 };
     SkAutoTUnref<SkColorTable> ctable(new SkColorTable(colors, SK_ARRAY_COUNT(colors)));
     // The colortable made a copy, so we can trash the original colors
     memset(colors, 0xFF, sizeof(colors));
 
     const SkImageInfo srcInfo = SkImageInfo::Make(2, 2, kIndex_8_SkColorType, kPremul_SkAlphaType);
@@ skipping 191 matching lines @@
         }
     }
 
     image.reset(nullptr);
     {
         SkBitmap cachedBitmap;
         REPORTER_ASSERT(reporter, !SkBitmapCache::Find(uniqueID, &cachedBitmap));
     }
 }
 #endif