Log message to console when any Tab's WebProcess crashes

Reviewed by: Sergio Correia
Update drowser after massive namespace and classes rename in Nix

Reviewed by: Hugo Lima
Change return value of audioHardwareSampleRate from double to float.

Change need to compile with newer version of Nix.

Reviewed by: Marcelo Lira
Don't redo things already done by the WebView.

Reviewed by: Lauro Neto
Remove unused include directives.

Reviewed by: Tullio Lucena
Added stubs for UserMediaClient.