Remove the MessageLoop::DestructionObserver from mojo bindings.

mojo/public/cpp/bindings/strong_associated_binding.h

Index: mojo/public/cpp/bindings/strong_associated_binding.h
diff --git a/mojo/public/cpp/bindings/strong_associated_binding.h b/mojo/public/cpp/bindings/strong_associated_binding.h
index 4d77a35ee8e4b0d485e1e4ce85353e4fe2c37739..4cb0c638e708637f0f8313ed8bf0ae967b7329e1 100644
--- a/mojo/public/cpp/bindings/strong_associated_binding.h
+++ b/mojo/public/cpp/bindings/strong_associated_binding.h
@@ -29,7 +29,9 @@ using StrongAssociatedBindingPtr =
     base::WeakPtr<StrongAssociatedBinding<Interface>>;
 
 // This connects an interface implementation strongly to an associated pipe.
-// When a connection error is detected the implementation is deleted.
+// When a connection error is detected the implementation is deleted. If the
+// task runner that a StrongBinding is bound on is stopped, the connection error

[yzshen1, 2017/01/26 23:58:20]

nit: StrongBinding -> StrongAssociatedBinding

[Sam McNally, 2017/01/27 04:54:20]

Done.

+// handler will not be invoked and the implementation will not be deleted.
 //
 // To use, call StrongAssociatedBinding<T>::Create() (see below) or the helper
 // MakeStrongAssociatedBinding function: