Add "Save Page As" to right click context menu
Add "Save Page As" to right click context menu

fix #4830

Auditors: @bsclifton

Test Plan:
1. right click on page
2. context menu should contain "Save Page As"

darkdh/browser-laptop,timborden/browser-laptop,willy-b/browser-laptop,Sh1d0w/browser-laptop,luixxiul/browser-laptop,luixxiul/browser-laptop,luixxiul/browser-laptop,dcposch/browser-laptop,diasdavid/browser-laptop,dcposch/browser-laptop,willy-b/browser-laptop,jonathansampson/browser-laptop,willy-b/browser-laptop,darkdh/browser-laptop,luixxiul/browser-laptop,darkdh/browser-laptop,Sh1d0w/browser-laptop,Sh1d0w/browser-laptop,pmkary/braver,willy-b/browser-laptop,diasdavid/browser-laptop,jonathansampson/browser-laptop,pmkary/braver,diasdavid/browser-laptop,darkdh/browser-laptop,jonathansampson/browser-laptop,dcposch/browser-laptop,pmkary/braver,diasdavid/browser-laptop,jonathansampson/browser-laptop,pmkary/braver,timborden/browser-laptop,dcposch/browser-laptop,timborden/browser-laptop,timborden/browser-laptop,Sh1d0w/browser-laptop