Incorporate BlobChannel into Blimp image encode/decode pipeline.

blimp/client/session/blimp_client_session.h

Index: blimp/client/session/blimp_client_session.h
diff --git a/blimp/client/session/blimp_client_session.h b/blimp/client/session/blimp_client_session.h
index fc8a42ef8902ba6ce2104f4da2d999232c378d80..7f7980ec62e3079b484aa4d4816d23565f906524 100644
--- a/blimp/client/session/blimp_client_session.h
+++ b/blimp/client/session/blimp_client_session.h
@@ -11,6 +11,7 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/threading/thread.h"
+#include "blimp/client/feature/compositor/client_image_serialization_processor.h"
 #include "blimp/client/session/assignment_source.h"
 #include "blimp/common/proto/blimp_message.pb.h"
 #include "blimp/net/blimp_connection_statistics.h"
@@ -24,8 +25,10 @@ namespace blimp {
 
 class BlimpMessageProcessor;
 class BlimpMessageThreadPipe;
+class BlobChannelReceiver;
 class BrowserConnectionHandler;
 class ClientConnectionManager;
+class HeliumBlobReceiverDelegate;
 class ThreadPipeManager;
 
 namespace client {
@@ -54,7 +57,9 @@ class NetworkEventObserver {
 // This session glues together the feature proxy components and the network
 // layer.  The network components must be interacted with on the IO thread.  The
 // feature proxies must be interacted with on the UI thread.
-class BlimpClientSession : public NetworkEventObserver {
+class BlimpClientSession
+    : public NetworkEventObserver,
+      public ClientImageSerializationProcessor::ErrorDelegate {
  public:
   explicit BlimpClientSession(const GURL& assigner_endpoint);
 
@@ -93,7 +98,16 @@ class BlimpClientSession : public NetworkEventObserver {
   void OnConnected() override;
   void OnDisconnected(int result) override;
 
+  // ClientImageSerializationProcessor::ErrorDelegate implementation.
+  void OnImageDecodeError() override;
+
   base::Thread io_thread_;
+
+  // Receives blob BlimpMessages and relays them to BlobChannelReceiver.
+  // Owned by BlobChannelReceiver, therefore stored as a raw pointer here.
+  HeliumBlobReceiverDelegate* blob_delegate_ = nullptr;
+
+  std::unique_ptr<BlobChannelReceiver> blob_receiver_;
   std::unique_ptr<TabControlFeature> tab_control_feature_;
   std::unique_ptr<NavigationFeature> navigation_feature_;
   std::unique_ptr<ImeFeature> ime_feature_;