Changing window.requestLayoutFrame into a microtask API

tools/dom/templates/html/dartium/impl_Window.darttemplate

Index: tools/dom/templates/html/dartium/impl_Window.darttemplate
diff --git a/tools/dom/templates/html/dartium/impl_Window.darttemplate b/tools/dom/templates/html/dartium/impl_Window.darttemplate
index 381e58ba007d2c6060c972c30788ab237e5be771..254d47270ca9261f829f4354259f5ccee4847ca2 100644
--- a/tools/dom/templates/html/dartium/impl_Window.darttemplate
+++ b/tools/dom/templates/html/dartium/impl_Window.darttemplate
@@ -7,12 +7,13 @@ part of html;
 $(ANNOTATIONS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 
   /**
-   * Executes a [callback] after the next batch of browser layout measurements
-   * has completed or would have completed if any browser layout measurements
-   * had been scheduled.
+   * Executes a [callback] after the immediate execution stack has completed.
+   *
+   * This will cause the callback to be executed after all processing has
+   * completed for the current event, but before any subsequent events.
    */
-  void requestLayoutFrame(TimeoutHandler callback) {
-    _addMeasurementFrameCallback(callback);
+  void setImmediate(TimeoutHandler callback) {
+    _addMicrotaskCallback(callback);
   }
 
   /**
@@ -34,5 +35,13 @@ $(ANNOTATIONS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
     document.documentElement.attributes['dart-port:$name'] = json.stringify(serialized);
   }
 
+  /// Checks if _setImmediate is supported.
+  static bool get _supportsSetImmediate => false;
+
+  /// Dartium stub for IE's setImmediate.
+  void _setImmediate(void callback()) {
+    throw new UnsupportedError('setImmediate is not supported');
+  }
+
 $!MEMBERS
 }