It should only be enabled when the view is focused and there's an editable element focused. In r138544, when input methods were implemented, the message SetInputMethodState was added, but it was never used. Instead, the notifyFocusIn method of the IM filter enables the input method unconditionally. We should actually use the SetInputMethodState message to enable/disable input methods when editable elements are focused/unfocused.
Created attachment 256832 [details]
Created attachment 256833 [details]
Also avoids updating the cursor rect if input methods are disabled.
Comment on attachment 256833 [details]
Seems reasonable to me.
Committed r186888: <http://trac.webkit.org/changeset/186888>