Oilpan: introduce sticky forcedForTesting flag to ensure that a precise

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

Index: LayoutTests/svg/animations/smil-leak-element-instances.svg
diff --git a/LayoutTests/svg/animations/smil-leak-element-instances.svg b/LayoutTests/svg/animations/smil-leak-element-instances.svg
index 560e41aa39d302c1afaba4b52abe2c459c10755f..88dcd8e839a8c06cd61e6c9f7e4ede086a24a4c7 100644
--- a/LayoutTests/svg/animations/smil-leak-element-instances.svg
+++ b/LayoutTests/svg/animations/smil-leak-element-instances.svg
@@ -32,24 +32,45 @@ function createAnimatedRectInstance() {
     return use;
 }
 
+// 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();
+    setTimeout(function() {
+        GCController.collect();
+        setTimeout(function() {
+            GCController.collect();
+            setTimeout(function() {
+                GCController.collect();
+                setTimeout(callback, 0);
+            }, 0);
+        }, 0);
+    }, 0);
+}
+
 function cleanup() {
     // Collect garbage before recording starting live node count, in case there are live elements from previous tests.
-    GCController.collectAll();
-    var originalLiveElements = internals.numberOfLiveNodes();
-
-    while (g.hasChildNodes())
-        g.removeChild(g.lastChild);
+    collectGarbage(function() {
+        var originalLiveElements = internals.numberOfLiveNodes();
 
-    GCController.collectAll();
+        while (g.hasChildNodes())
+            g.removeChild(g.lastChild);
 
-    // This is 400 instead of 200 as it creates shadow tree elements.
-    var liveDelta = originalLiveElements - internals.numberOfLiveNodes() - 400;
-    if (liveDelta == 0)
-        log("PASS");
-    else
-        log("FAIL: " + liveDelta + " extra live node(s)");
+        collectGarbage(function() {
+            // This is 400 instead of 200 as it creates shadow tree elements.
+            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]

Also can't we waitUntilDone here to not exit until the gc is complete?

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

Already done in the load function.

 
 function startTest() {