Rename tab_manager_grc_tab_signal_observer to page_signal_receiver
Rename tab_manager_grc_tab_signal_observer to page_signal_receiver

https://crrev.com/04e78cc6816

brave/electron,brave/muon,brave/muon,brave/electron,brave/electron,brave/electron,brave/muon,brave/muon,brave/muon,brave/electron,brave/electron,brave/muon