Incorporate BlobChannel into Blimp image encode/decode pipeline.

blimp/client/feature/compositor/decoding_image_generator.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "blimp/client/feature/compositor/decoding_image_generator.h"
 
 #include "base/numerics/safe_conversions.h"
 #include "blimp/client/feature/compositor/blimp_image_decoder.h"
+#include "blimp/client/feature/compositor/client_image_serialization_processor.h"
 #include "blimp/common/proto/blob_cache.pb.h"
 #include "third_party/libwebp/webp/decode.h"
 #include "third_party/libwebp/webp/demux.h"
 #include "third_party/skia/include/core/SkData.h"
 
 namespace blimp {
 namespace client {
 
 SkImageGenerator* DecodingImageGenerator::create(SkData* data) {
   BlobCacheImageMetadata parsed_metadata;
   int signed_size = base::checked_cast<int>(data->size());
   if (!parsed_metadata.ParseFromArray(data->data(), signed_size)) {
     // Failed to parse proto, so will fail to decode later as well. Inform
     // Skia by giving back an empty SkImageInfo.
     return new DecodingImageGenerator(SkImageInfo::MakeN32Premul(0, 0),
                                       data->data(), data->size());
   }
 
   return new DecodingImageGenerator(
       SkImageInfo::MakeN32Premul(parsed_metadata.width(),
                                  parsed_metadata.height()),
       data->data(), data->size());
 }
 
 DecodingImageGenerator::DecodingImageGenerator(const SkImageInfo info,
                                                const void* data,
                                                size_t size)
     : SkImageGenerator(info) {
-  BlimpImageDecoder(data, size, &decoded_bitmap_);
+  if (!ClientImageSerializationProcessor::GetInstance()->GetAndDecodeBlob(
+          data, size, &decoded_bitmap_)) {
+    DLOG(WARNING) << "GetAndDecodeBlob failed.";

[Wez, 2016/05/21 01:08:03]

All the failure code paths in GetAndDecodeBlob already log something; suggest
logging inside, or outside, but not both!

If GetAndDecodeBlob fails here then something is seriously wrong - can we
restructure this to allow us to propagate the failure and disconnect the session
in this case?

[Kevin M, 2016/05/27 22:35:29]

Done, see set_error_delegate for error reporting.

Upgraded this to DLOG(FATAL) so that this will break on debug builds when
GetAndDecodeBlob fails.

[Wez, 2016/06/07 01:18:31]

I don't understand why we need the error delegate on the
ClientImageSerializationProcessor - isn't it effectively the same as the false
return-value here, in which case why does this class not handle it?  Why do we
need both the delegate and the return-value?

nit: Seems redundant to say "GetAndDecodeBlob() failed" here - you might just
do:

bool result = GetAndDecodeBlob()
DCHECK(result);

+  }
 }
 
 DecodingImageGenerator::~DecodingImageGenerator() {}
 
 bool DecodingImageGenerator::onGetPixels(const SkImageInfo& info,
                                          void* pixels,
                                          size_t rowBytes,
                                          SkPMColor table[],
                                          int* tableCount) {
   SkAutoLockPixels bitmapLock(decoded_bitmap_);
   if (decoded_bitmap_.getPixels() != pixels) {
     return decoded_bitmap_.copyPixelsTo(pixels, rowBytes * info.height(),
                                         rowBytes);
   }
   return true;
 }
 
 bool DecodingImageGenerator::onQueryYUV8(SkYUVSizeInfo* sizeInfo,
                                          SkYUVColorSpace* colorSpace) const {
   return false;
 }
 
 bool DecodingImageGenerator::onGetYUV8Planes(const SkYUVSizeInfo& sizeInfo,
                                              void* planes[3]) {
   return false;
 }
 
 }  // namespace client
 }  // namespace blimp