Migrate TabControlFeature from 0.5 to 0.6

blimp/client/core/blimp_client_context_impl.h

Index: blimp/client/core/blimp_client_context_impl.h
diff --git a/blimp/client/core/blimp_client_context_impl.h b/blimp/client/core/blimp_client_context_impl.h
index e108782858c9b464d5829ef7c3cc4413b5ab8a4a..8f8ab63d0386e08ac1cc976b168b880c4a04fb88 100644
--- a/blimp/client/core/blimp_client_context_impl.h
+++ b/blimp/client/core/blimp_client_context_impl.h
@@ -22,6 +22,8 @@
 namespace blimp {
 namespace client {
 
+class BlimpContentsManager;
+
 // BlimpClientContextImpl is the implementation of the main context-class for
 // the blimp client.
 class BlimpClientContextImpl : public BlimpClientContext,
@@ -52,6 +54,8 @@ class BlimpClientContextImpl : public BlimpClientContext,
   // transferred over network. Owned by ClientNetworkComponents.
   BlimpConnectionStatistics* blimp_connection_statistics_;
 
+  std::unique_ptr<BlimpContentsManager> blimp_contents_manager_;
+
   // Container struct for network components.
   // Must be deleted on the IO thread.
   std::unique_ptr<ClientNetworkComponents> net_components_;