Incorporate BlobChannel into Blimp image encode/decode pipeline.

blimp/engine/renderer/engine_image_serialization_processor.h

Index: blimp/engine/renderer/engine_image_serialization_processor.h
diff --git a/blimp/engine/renderer/engine_image_serialization_processor.h b/blimp/engine/renderer/engine_image_serialization_processor.h
index d400704b15f52da6187b841a42a9fe9adf5a8b65..387cee61405b5de3af92efd23895d677b5f659f6 100644
--- a/blimp/engine/renderer/engine_image_serialization_processor.h
+++ b/blimp/engine/renderer/engine_image_serialization_processor.h
@@ -22,13 +22,15 @@ class RenderFrame;
 namespace blimp {
 namespace engine {
 
+class BlobChannelSenderHost;
+
 // EngineImageSerializationProcessor provides functionality to serialize and
 // deserialize Skia images.
 class BLIMP_COMMON_EXPORT EngineImageSerializationProcessor
     : public cc::ImageSerializationProcessor {
  public:
   explicit EngineImageSerializationProcessor(
-      mojom::BlobChannelPtr blob_channel);
+      std::unique_ptr<BlobChannelSenderHost> blob_channel);
   ~EngineImageSerializationProcessor();
 
   // cc::ImageSerializationProcessor implementation.
@@ -37,7 +39,7 @@ class BLIMP_COMMON_EXPORT EngineImageSerializationProcessor
 
  private:
   std::unique_ptr<SkPixelSerializer> pixel_serializer_;
-  mojom::BlobChannelPtr blob_channel_;
+  std::unique_ptr<BlobChannelSenderHost> blob_channel_;
 
   DISALLOW_COPY_AND_ASSIGN(EngineImageSerializationProcessor);
 };