Add ticks counter to Timer.

sdk/lib/_internal/js_runtime/lib/preambles/d8.js

Index: sdk/lib/_internal/js_runtime/lib/preambles/d8.js
diff --git a/sdk/lib/_internal/js_runtime/lib/preambles/d8.js b/sdk/lib/_internal/js_runtime/lib/preambles/d8.js
index ca9093756e46bee93a6cdc15d041a9c7a6811376..00f2485248e46a10871650dad74ae93d801b0ae9 100644
--- a/sdk/lib/_internal/js_runtime/lib/preambles/d8.js
+++ b/sdk/lib/_internal/js_runtime/lib/preambles/d8.js
@@ -15,7 +15,6 @@ if (typeof global != "undefined") self = global;  // Node.js.
   "use strict"; // Should be first statement of this function.
 
   // Location (Uri.base)
-
   var baseUri = 'org-dartlang-d8-preamble:///mock/uri/base/';
   if (typeof process != "undefined" &&
              typeof process.cwd == "function") {
@@ -78,7 +77,7 @@ if (typeof global != "undefined") self = global;  // Node.js.
     var id = timerIdCounter++;
     f.$timerId = id;
     timerIds[id] = f;
-    if (ms == 0) {
+    if (ms == 0 && !isNextTimerDue()) {
       zeroTimerQueue.push(f);
     } else {
       addDelayedTimer(f, ms);
@@ -127,7 +126,10 @@ if (typeof global != "undefined") self = global;  // Node.js.
   var originalDate = Date;
   var originalNow = originalDate.now;
   function advanceTimeTo(time) {
-    timeOffset = time - originalNow();
+    var now = originalNow();
+    if (timeOffset < time - now) {
+      timeOffset = time - now;
+    }
   }
   function installMockDate() {
     var NewDate = function Date(Y, M, D, h, m, s, ms) {
@@ -172,6 +174,12 @@ if (typeof global != "undefined") self = global;  // Node.js.
     }
   }
 
+  function isNextTimerDue() {
+    if (timerHeap.length == 0) return false;
+    var head = timerHeap[0];
+    return head[0] < originalNow() + timeOffset;
+  }
+
   function nextDelayedTimerQueue() {
     if (timerHeap.length == 0) return null;
     var result = timerHeap[0];
@@ -261,7 +269,7 @@ if (typeof global != "undefined") self = global;  // Node.js.
 
   // Global properties. "self" refers to the global object, so adding a
   // property to "self" defines a global variable.
-  self.self = self
+  self.self = self;
   self.dartMainRunner = function(main, args) {
     // Initialize.
     var action = function() { main(args); }