Add Script Console Output and Errors

[GoogleCodeExporter]

As applications get more complicated, and as optimizations take more advantage 
of the available technologies, scripts play a bigger and more fragile role. 

Measuring performance when the page is actually broken isn't very useful, so 
getting information about script errors that happened during the load is very 
important. This is most important when using WPT scripts, and when testing 
across browsers. 

On a similar note, when debugging these problems the console output is the 
primary (and only) way to log information from javascript out to the debugging 
tools. 

In short, it'll be great if WPT captured and displayed script errors and 
console output.
If necessary, this can be an optional feature, as sometimes capturing console 
output changes the application behavior.

Original issue reported on code.google.com by guy...@gmail.com on 15 Sep 2011 at 3:09

[GoogleCodeExporter]

Original comment by PatMee...@gmail.com on 11 Jan 2012 at 4:24

• Changed state: Accepted

[GoogleCodeExporter]

This has been implemented for Chrome (log events show up in the screen shot 
page).  Until Firefox and IE provide a standard wat to retrieve the information 
it won't be implemented elsewhere.

Original comment by PatMee...@gmail.com on 13 Feb 2012 at 2:51

• Changed state: Fixed

[GoogleCodeExporter]

The firefox extension code has the ability to log errors for individual script 
commands to the firefox console.  It might not be as complete as chrome's web 
console, but there is substantial usfull information scripts could send back.  
Opened issue 66 to track.

Original comment by sker...@google.com on 13 Feb 2012 at 3:16