ImeCommitText
Completes the existing composition by optionally inserting the specified |text| into the composition node.
See comments on ImeSetComposition for usage.
This method is only used when window rendering is disabled.
Parameters
text
text to be committed
replacementRange
an optional range of the existing text that will be replaced(the value is only used on OS X)
relativeCursorPos
where the cursor will be positioned relative to the current cursor position(the value is only used on OS X)