Summary:
Instead of just blindly retrying all ViewCommands if they fail - which could be dangerous, since it's arbitrary imperative commands we'd be executing twice, potentially with bad app state - we only retry if the ViewCommand throws a "RetryableMountingLayerException".
Changelog: [Internal] Optimization to ViewCommands
Reviewed By: mdvacca
Differential Revision: D20529985
fbshipit-source-id: 0217b43f4bf92442bcc7ca48c8ae2b9a9e543dc9