Kill Servo instead of displaying about:failure when running content tests

Fixes #1380.

src/components/gfx/opts.rs

@@ -39,6 +39,7 @@ pub struct Opts {
 
     output_file: Option<~str>,
     headless: bool,
+    hard_fail: bool,
 }
 
 fn print_usage(app: &str, opts: &[groups::OptGroup]) {
@@ -59,6 +60,7 @@ pub fn from_cmdline_args(args: &[~str]) -> Opts {
         groups::optflagopt("p", "profile", "Profiler flag and output interval", "10"),
         groups::optflag("x", "exit", "Exit after load flag"),
         groups::optflag("z", "headless", "Headless mode"),
+        groups::optflag("f", "hard-fail", "Exit on task failure instead of displaying about:failure"),
         groups::optflag("h", "help", "Print this message")
     ];
 
@@ -127,5 +129,6 @@ pub fn from_cmdline_args(args: &[~str]) -> Opts {
         exit_after_load: opt_match.opt_present("x"),
         output_file: opt_match.opt_str("o"),
         headless: opt_match.opt_present("z"),
+        hard_fail: opt_match.opt_present("f"),
     }
 }

src/components/main/pipeline.rs

@@ -100,6 +100,7 @@ impl Pipeline {
 
         // Wrap task creation within a supervised task so that failure will
         // only tear down those tasks instead of ours.
+        let hard_fail = opts.hard_fail;
         let failure_chan = constellation_chan.clone();
         let mut supervised_task = task::task();
         let task_port = supervised_task.future_result();
@@ -139,6 +140,9 @@ impl Pipeline {
             match task_port.recv() {
                 Ok(*) => (),
                 Err(*) => {
+                    if hard_fail {
+                        fail!("Pipeline failed in hard-fail mode");
+                    }
                     failure_chan.send(FailureMsg(id, subpage_id));
                 }
             }

src/test/harness/contenttest/contenttest.rs

@@ -93,7 +93,7 @@ fn run_test(file: ~str) {
 
     let config = ProcessConfig {
         program: "./servo",
-        args: [~"-z", infile.clone()],
+        args: [~"-z", ~"-f", infile.clone()],
         env: None,
         cwd: None,
         io: [Ignored, stdout, stderr]