change write-image to use pipeverbs like everyone else, and add test

src/pipe/SkPipeCanvas.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPathEffect.h"
 #include "SkColorFilter.h"
 #include "SkDrawLooper.h"
@@ skipping 1019 matching lines @@
 
 void SkPipeSerializer::write(SkPicture* picture, SkWStream* stream) {
     stream->write32(kDefinePicture_ExtPipeVerb);
     SkRect cull = picture->cullRect();
     stream->write(&cull.fLeft, sizeof(SkRect));
     picture->playback(this->beginWrite(cull, stream));
     this->endWrite();
 }
 
 void SkPipeSerializer::write(SkImage* image, SkWStream* stream) {
-    stream->write32(kDefineImage_ExtPipeVerb);
-    SkPipeWriter writer(stream, &fImpl->fDeduper);
-    writer.writeImage(image);
+    int index = fImpl->fDeduper.findImage(image);
+    if (0 == index) {
+        // Try to define the image
+        fImpl->fDeduper.setStream(stream);
+        index = fImpl->fDeduper.findOrDefineImage(image);
+    }
+    stream->write32(pack_verb(SkPipeVerb::kWriteImage, index));
 }
 
 SkCanvas* SkPipeSerializer::beginWrite(const SkRect& cull, SkWStream* stream) {
     SkASSERT(nullptr == fImpl->fCanvas);
     fImpl->fCanvas.reset(new SkPipeCanvas(cull, &fImpl->fDeduper, stream));
     fImpl->fDeduper.setStream(stream);
     fImpl->fDeduper.setCanvas(fImpl->fCanvas.get());
     return fImpl->fCanvas.get();
 }
 
 void SkPipeSerializer::endWrite() {
     fImpl->fCanvas->restoreToCount(1);
     fImpl->fCanvas.reset(nullptr);
+    fImpl->fDeduper.setCanvas(nullptr);
 }