Changes to layout_task.rs and window.rs

layout_task.rs

use cssparser::{Parser, SourcePosition};

struct CSSErrorReporter {
}

impl ParseErrorReporter for CSSErrorReporter {
      fn report_error(&self, input: &mut Parser, position: SourcePosition, message: &str) {
          if log_enabled!(log::LogLevel::Info) {
        let location = input.source_location(position);
        // TODO eventually this will got into a "web console" or something.
        info!("{}:{} {}", location.line, location.column, message)
        }   
     
     }
     
     fn clone(&self) -> Box<ParseErrorReporter + Send> {
       
       let error_reporter=Box::new(CSSErrorReporter);
       return error_reporter;
     }
}

window.rs

use layout_task::CSSErrorReporter;
pub fn css_error_reporter(&self) -> Box<ParseErrorReporter+Send> {
    
        let error_reporter = Box::new(CSSErrorReporter);
        
        return error_reporter;
    }