Auto merge of #7651 - jgraham:prefs_reset, r=Ms2ger

Implement resettable and String-valued prefs.



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tests/reftest.rs

@@ -25,6 +25,7 @@ use std::io::{self, Read, Result};
 use std::path::{Path, PathBuf};
 use std::process;
 use std::process::{Command, Stdio};
+use std::thread::sleep_ms;
 use test::run_tests_console;
 use test::{AutoColor, DynTestName, DynTestFn, TestDesc, TestOpts, TestDescAndFn, ShouldPanic};
 use url::Url;
@@ -111,10 +112,22 @@ fn run(test_opts: TestOpts, all_tests: Vec<TestDescAndFn>,
     // Verify that we're passing in valid servo arguments. Otherwise, servo
     // will exit before we've run any tests, and it will appear to us as if
     // all the tests are failing.
-    let output = match Command::new(&servo_path()).args(&servo_args).output() {
+    let mut command = Command::new(&servo_path());
+    command
+        .args(&servo_args)
+        .arg("-z")
+        .arg("about:blank");
+
+    let mut child = match command.spawn() {
         Ok(p) => p,
         Err(e) => panic!("failed to execute process: {}", e),
     };
+
+    // Wait for the shell to launch or to fail
+    sleep_ms(1000);
+    child.kill().unwrap();
+    let output = try!(child.wait_with_output());
+
     let stderr = String::from_utf8(output.stderr).unwrap();
 
     if stderr.contains("Unrecognized") {

tests/unit/style/viewport.rs

@@ -26,7 +26,8 @@ fn test_viewport_rule<F>(css: &str,
                          callback: F)
     where F: Fn(&Vec<ViewportDescriptorDeclaration>, &str)
 {
-    ::util::prefs::set_pref("layout.viewport.enabled", true);
+    ::util::prefs::set_pref("layout.viewport.enabled",
+                            ::util::prefs::PrefValue::Boolean(true));
 
     let stylesheet = stylesheet!(css, Author);
     let mut rule_count = 0;
@@ -173,7 +174,8 @@ fn cascading_within_viewport_rule() {
 
 #[test]
 fn multiple_stylesheets_cascading() {
-    ::util::prefs::set_pref("layout.viewport.enabled", true);
+    ::util::prefs::set_pref("layout.viewport.enabled",
+                            ::util::prefs::PrefValue::Boolean(true));
     let device = Device::new(MediaType::Screen, Size2D::typed(800., 600.));
 
     let stylesheets = vec![