Blimp: Add BlobChannel Helium messages and delegate impls.

blimp/common/create_blimp_message.h

Index: blimp/common/create_blimp_message.h
diff --git a/blimp/common/create_blimp_message.h b/blimp/common/create_blimp_message.h
index ab8a16dd873e1ea1e89375e3979c6b10ea976e05..e201459c67e15319c93539236fd77bfff8a8342e 100644
--- a/blimp/common/create_blimp_message.h
+++ b/blimp/common/create_blimp_message.h
@@ -15,6 +15,7 @@
 namespace blimp {
 
 class BlimpMessage;
+class BlobChannelMessage;
 class CompositorMessage;
 class EngineSettingsMessage;
 class ImeMessage;
@@ -66,6 +67,9 @@ BLIMP_COMMON_EXPORT std::unique_ptr<BlimpMessage> CreateBlimpMessage(
 BLIMP_COMMON_EXPORT std::unique_ptr<BlimpMessage> CreateBlimpMessage(
     EngineSettingsMessage** engine_settings);
 
+BLIMP_COMMON_EXPORT std::unique_ptr<BlimpMessage> CreateBlimpMessage(
+    BlobChannelMessage** blob_channel_message);
+
 BLIMP_COMMON_EXPORT std::unique_ptr<BlimpMessage> CreateStartConnectionMessage(
     const std::string& client_token,
     int protocol_version);