Support early associated interface binding on ChannelMojo

ipc/ipc_channel.h

Index: ipc/ipc_channel.h
diff --git a/ipc/ipc_channel.h b/ipc/ipc_channel.h
index 8d886b51f19d3ea410a9eddd655051f395b3caed..a1917d936601803829328b8b0b80d4f8271a0a7b 100644
--- a/ipc/ipc_channel.h
+++ b/ipc/ipc_channel.h
@@ -103,10 +103,11 @@ class IPC_EXPORT Channel : public Endpoint {
     virtual ~AssociatedInterfaceSupport() {}
 
     // Accesses the AssociatedGroup used to associate new interface endpoints
-    // with this Channel.
+    // with this Channel. Must be safe to call from any thread.
     virtual mojo::AssociatedGroup* GetAssociatedGroup() = 0;
 
-    // Adds an interface factory to this channel for interface |name|.
+    // Adds an interface factory to this channel for interface |name|. Must be
+    // safe to call from any thread.
     virtual void AddGenericAssociatedInterface(
         const std::string& name,
         const GenericAssociatedInterfaceFactory& factory) = 0;
@@ -116,11 +117,6 @@ class IPC_EXPORT Channel : public Endpoint {
         const std::string& name,
         mojo::ScopedInterfaceEndpointHandle handle) = 0;
 
-    // Sets the TaskRunner on which to support proxied dispatch for associated
-    // interfaces.
-    virtual void SetProxyTaskRunner(
-        scoped_refptr<base::SingleThreadTaskRunner> task_runner) = 0;
-
     // Template helper to add an interface factory to this channel.
     template <typename Interface>
     using AssociatedInterfaceFactory =