Called when the main frame changes due to (a) initial browser creation,
(b) final browser destruction, (c) cross-origin navigation or (d) re-
navigation after renderer process termination (due to crashes, etc).
|old_frame| will be NULL and |new_frame| will be non-NULL when a main
frame is assigned to |browser| for the first time. |old_frame| will be
non-NULL and |new_frame| will be NULL and when a main frame is removed
from |browser| for the last time. Both |old_frame| and |new_frame| will be
non-NULL for cross-origin navigations or re-navigation after renderer
process termination. This function will be called after on_frame_created()
for |new_frame| and/or after on_frame_detached() for |old_frame|. If
called after cef_life_span_handler_t::on_before_close() during browser
destruction then cef_browser_t::is_valid() will return false (0) for
|browser|.
Called when the main frame changes due to (a) initial browser creation, (b) final browser destruction, (c) cross-origin navigation or (d) re- navigation after renderer process termination (due to crashes, etc). |old_frame| will be NULL and |new_frame| will be non-NULL when a main frame is assigned to |browser| for the first time. |old_frame| will be non-NULL and |new_frame| will be NULL and when a main frame is removed from |browser| for the last time. Both |old_frame| and |new_frame| will be non-NULL for cross-origin navigations or re-navigation after renderer process termination. This function will be called after on_frame_created() for |new_frame| and/or after on_frame_detached() for |old_frame|. If called after cef_life_span_handler_t::on_before_close() during browser destruction then cef_browser_t::is_valid() will return false (0) for |browser|.