Re-add Mock Clock behavior as global 'clock'

- Use clock.install, clock.tick...
- Add unit coverage.
- Fixes old bug in function scheduler

src/core/Clock.js

@@ -0,0 +1,93 @@
+jasmine.Clock = function(global, delayedFunctionScheduler) {
+  var self = this,
+  realTimingFunctions = {
+    setTimeout: global.setTimeout,
+    clearTimeout: global.clearTimeout,
+    setInterval: global.setInterval,
+    clearInterval: global.clearInterval
+  },
+  fakeTimingFunctions = {
+    setTimeout: setTimeout,
+    clearTimeout: clearTimeout,
+    setInterval: setInterval,
+    clearInterval: clearInterval
+  },
+  timer = realTimingFunctions,
+  installed = false;
+
+  self.install = function() {
+    installed = true;
+    timer = fakeTimingFunctions;
+  };
+
+  self.uninstall = function() {
+    delayedFunctionScheduler.reset();
+    installed = false;
+    timer = realTimingFunctions;
+  };
+
+  self.setTimeout = function(fn, delay, params) {
+    if (legacyIE()) {
+      if (arguments.length > 2) {
+        throw new Error("IE < 9 cannot support extra params to setTimeout without a polyfill");
+      }
+      return timer.setTimeout(fn, delay);
+    }
+    return timer.setTimeout.apply(null, arguments);
+  };
+
+  self.setInterval = function(fn, delay, params) {
+    if (legacyIE()) {
+      if (arguments.length > 2) {
+        throw new Error("IE < 9 cannot support extra params to setInterval without a polyfill");
+      }
+      return timer.setInterval(fn, delay);
+    }
+    return timer.setInterval.apply(null, arguments);
+  };
+
+  self.clearTimeout = function(id) {
+    return timer.clearTimeout(id);
+  };
+
+  self.clearInterval = function(id) {
+    return timer.clearInterval(id);
+  };
+
+  self.tick = function(millis) {
+    if (installed) {
+      delayedFunctionScheduler.tick(millis)
+    } else {
+      throw new Error("Mock clock is not installed, use jasmine.Clock.useMock()");
+    }
+  };
+
+  return self;
+
+  function legacyIE() {
+    //if these methods are polyfilled, apply will be present
+    //TODO: it may be difficult to load the polyfill before jasmine loads
+    //(env should be new-ed inside of onload)
+    return !(global.setTimeout || global.setInterval).apply;
+  }
+
+  function setTimeout(fn, delay) {
+    return delayedFunctionScheduler.scheduleFunction(fn, delay, argSlice(arguments,2));
+  }
+
+  function clearTimeout(id) {
+    return delayedFunctionScheduler.removeFunctionWithId(id);
+  }
+
+  function setInterval(fn, interval) {
+    return delayedFunctionScheduler.scheduleFunction(fn, interval, argSlice(arguments, 2), true);
+  }
+
+  function clearInterval(id) {
+    return delayedFunctionScheduler.removeFunctionWithId(id);
+  }
+
+  function argSlice(argsObj, n) {
+    return Array.prototype.slice.call(argsObj, 2);
+  }
+};