SkPixelSerializer: support indexed pixels

src/image/SkImage.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkBitmapCache.h"
 #include "SkCanvas.h"
@@ skipping 167 matching lines @@
     return nullptr;
 }
 
 namespace {
 
 class DefaultSerializer :  public SkPixelSerializer {
 protected:
     bool onUseEncodedData(const void *data, size_t len) override {
         return true;
     }
-
-    SkData* onEncodePixels(const SkImageInfo& info, const void* pixels, size_t rowBytes) override {
-        return SkImageEncoder::EncodeData(info, pixels, rowBytes, SkImageEncoder::kPNG_Type, 100);
+    SkData* onEncode(const SkPixmap& pixmap) override {
+        SkBitmap bm;
+        return bm.installPixels(pixmap.info(),

[scroggo, 2015/12/07 15:57:07]

nit: I think this would be easier to follow if you separate it out into multiple
statements. e.g.

if (!bm.installPixels(...))
  return nullptr;

return SkImageEncoder::EncodeData(...);

Maybe that's just a matter of preference though.

[hal.canary, 2015/12/07 20:25:01]

done

+                                const_cast<void*>(pixmap.addr()),
+                                pixmap.rowBytes(),
+                                pixmap.ctable(),
+                                nullptr, nullptr)
+            ? SkImageEncoder::EncodeData(bm, SkImageEncoder::kPNG_Type, 100)
+            : nullptr;
     }
 };
 
 } // anonymous namespace
 
 SkData* SkImage::encode(SkPixelSerializer* serializer) const {
     DefaultSerializer defaultSerializer;
     SkPixelSerializer* effectiveSerializer = serializer ? serializer : &defaultSerializer;
 
     SkAutoTUnref<SkData> encoded(this->refEncoded());
@@ skipping 216 matching lines @@
 
 SkImage* SkImage::NewFromAdoptedTexture(GrContext*, const GrBackendTextureDesc&, SkAlphaType) {
     return nullptr;
 }
 
 SkImage* SkImage::NewFromTextureCopy(GrContext*, const GrBackendTextureDesc&, SkAlphaType) {
     return nullptr;
 }
 
 #endif