Convert IntersectionObserver tests to use testRunner.runIdleTasks.

third_party/WebKit/LayoutTests/LeakExpectations

Index: third_party/WebKit/LayoutTests/LeakExpectations
diff --git a/third_party/WebKit/LayoutTests/LeakExpectations b/third_party/WebKit/LayoutTests/LeakExpectations
index 21a956466155086060ae3c61f5bae9e7b0552202..b4244b36e76b21f76cd419c9e2a54cd3aea0cedd 100644
--- a/third_party/WebKit/LayoutTests/LeakExpectations
+++ b/third_party/WebKit/LayoutTests/LeakExpectations
@@ -151,20 +151,3 @@ crbug.com/594309 [ Linux ] imported/csswg-test/vendor-imports/mozilla/mozilla-ce
 crbug.com/594309 [ Linux ] imported/csswg-test/vendor-imports/mozilla/mozilla-central-reftests/variables/variable-declaration-18.html [ Leak ]
 crbug.com/594309 [ Linux ] imported/csswg-test/vendor-imports/mozilla/mozilla-central-reftests/variables/variable-external-font-face-01.html [ Pass Leak ]
 crbug.com/594309 [ Linux ] imported/csswg-test/vendor-imports/mozilla/mozilla-central-reftests/variables/variable-font-face-02.html [ Pass Leak ]
-
-# -----------------------------------------------------------------
-# Leaks in ScriptedIdleTaskController
-# See LayoutTests/intersection-observer/README for details.
-# -----------------------------------------------------------------
-crbug.com/595155 http/tests/intersection-observer/iframe-cross-origin.html [ Leak ]
-crbug.com/595155 intersection-observer/containing-block.html [ Leak ]
-crbug.com/606491 intersection-observer/edge-inclusive-intersection.html [ Leak ]
-crbug.com/595155 intersection-observer/iframe-no-root.html [ Leak ]
-crbug.com/595155 intersection-observer/multiple-thresholds.html [ Leak ]
-crbug.com/595155 intersection-observer/observer-without-js-reference.html [ Leak ]
-crbug.com/595155 intersection-observer/root-margin.html [ Leak ]
-crbug.com/595155 intersection-observer/same-document-no-root.html [ Leak ]
-crbug.com/595155 intersection-observer/same-document-root.html [ Leak ]
-crbug.com/595155 intersection-observer/same-document-zero-size-target.html [ Leak ]
-crbug.com/595155 intersection-observer/timestamp.html [ Leak ]
-crbug.com/595155 intersection-observer/unclipped-root.html [ Leak ]