How to assign a service keyboard shortcut for a specific application (non global)?
Going from your example, I assume:


You have an existing Automator service that reloads a Chrome tab.
It is set to work in TextEdit only.
It is installed (in ~/Library/Services).


To set an application-specific shortcut then:


Open System Preferences > Keyboard 
Go to the Shortcuts tab and choose App Shortcuts at the bottom of the list.
Create a new shortcut:


Restrict the shortcut to TextEdit
The name must be exactly the same as the menu title of the service