Automate sequence of key strokes in Mac

To do this, I created a automator workflow with a Run AppleScript object with this content:

on run {input, parameters}

tell application "Google Chrome" to activate

tell application "System Events"
    keystroke "A"
    keystroke "B"
    keystroke "C"
end tell

return input
 end run

This worked fine for me

In addition to writing your own script, Keyboard Maestro can be used to compose key sequences like this.

You could create a macro with an application like Keyboard Maestro, iKey or QuicKeys. Many of them also support something like the quick macros in Keyboard Maestro. You can press ⌃F1 to start or stop recording a macro, and then play it back with ⌥F1.

You can also emulate keypresses with AppleScript. The delay at the start is not needed if the script is run with FastScripts.

delay 0.5 -- if the script is run with a shortcut that has modifier keys
activate application "TextEdit"
tell application "System Events"
    keystroke "aa"
    key code 123 using {shift down, command down}
end tell

The keystroke command can only be used to insert characters that are included in the current keyboard layout. If the text is long enough, there's also a visible delay when it's inserted.

Another way to insert text is to use the clipboard:

set the clipboard to "aa"
delay 0.05
tell application "System Events" to keystroke "v" using command down