Oilpan: introduce sticky forcedForTesting flag to ensure that a precise

LayoutTests/svg/animations/smil-leak-dynamically-added-element-instances.svg

Index: LayoutTests/svg/animations/smil-leak-dynamically-added-element-instances.svg
diff --git a/LayoutTests/svg/animations/smil-leak-dynamically-added-element-instances.svg b/LayoutTests/svg/animations/smil-leak-dynamically-added-element-instances.svg
index b7ecf34e878d9526be78392c3239741fe6e33cfa..8a254b6d89ced0dc6ff5d26b8b8e0c7eff3a24e9 100644
--- a/LayoutTests/svg/animations/smil-leak-dynamically-added-element-instances.svg
+++ b/LayoutTests/svg/animations/smil-leak-dynamically-added-element-instances.svg
@@ -32,26 +32,44 @@ function createAnimatedRectInstance() {
     return use;
 }
 
-function cleanup() {
-    // Collect garbage before recording starting live node count, in case there are live elements from previous tests.
-    // FIXME: Unclear why two calls to collect() are required, see crbug.com/307614
-    GCController.collect();
+// With Oilpan tests that rely on garbage collection need to go through
+// the event loop in order to get precise garbage collections. Oilpan
+// uses conservative stack scanning when not at the event loop and that
+// can artificially keep objects alive. Therfore, test that need to check

[wibling-chromium, 2014/04/01 13:26:09]

Ditto.

[Mads Ager (chromium), 2014/04/01 13:45:38]

Done.

+// that something is dead need to use this asynchronous collectGarbage
+// function.
+function collectGarbage(callback) {
     GCController.collect();
-    var originalLiveElements = internals.numberOfLiveNodes();
+    setTimeout(function() {
+        GCController.collect();
+        setTimeout(function() {
+            GCController.collect();
+            setTimeout(function() {
+                GCController.collect();
+                setTimeout(callback, 0);
+            }, 0);
+        }, 0);
+    }, 0);
+}
 
-    while (g.hasChildNodes())
-        g.removeChild(g.lastChild);
+function cleanup() {
+    collectGarbage(function() {
+        var originalLiveElements = internals.numberOfLiveNodes();
 
-    GCController.collect();
+        while (g.hasChildNodes())
+            g.removeChild(g.lastChild);
 
-    // FIXME: Why 400 and not 200?
-    var liveDelta = originalLiveElements - internals.numberOfLiveNodes() - 400;
-    if (liveDelta == 0)
-        log("PASS");
-    else
-        log("FAIL: " + liveDelta + " extra live node(s)");
+        collectGarbage(function() {
+            // FIXME: Why 400 and not 200?
+            var liveDelta = originalLiveElements - internals.numberOfLiveNodes() - 400;
+            if (liveDelta == 0)
+                log("PASS");
+            else
+                log("FAIL: " + liveDelta + " extra live node(s)");
 
-    testRunner.notifyDone();
+            testRunner.notifyDone();
+        });
+    });
 }

[wibling-chromium, 2014/04/01 13:26:09]

Could you do a testRunner.waitUntilDone() here to avoid exiting until the gc's
are complete?

[Mads Ager (chromium), 2014/04/01 13:45:38]

That has already been done. In the onload event we call the "load" function.
That makes sure to waitUntilDone and calls startTest via the event loop.

 
 function addMoreInstances() {