Oilpan: improve resource-tree-mimetype.html stability.

LayoutTests/http/tests/inspector-enabled/resource-tree/resource-tree-mimetype.html

Index: LayoutTests/http/tests/inspector-enabled/resource-tree/resource-tree-mimetype.html
diff --git a/LayoutTests/http/tests/inspector-enabled/resource-tree/resource-tree-mimetype.html b/LayoutTests/http/tests/inspector-enabled/resource-tree/resource-tree-mimetype.html
index b40aea8d93da485524a90b5df923549d1dfea321..0f00801c3ab262a57eaa7e5ae9df86d6d630df28 100644
--- a/LayoutTests/http/tests/inspector-enabled/resource-tree/resource-tree-mimetype.html
+++ b/LayoutTests/http/tests/inspector-enabled/resource-tree/resource-tree-mimetype.html
@@ -10,6 +10,13 @@ function onload()
         testRunner.waitUntilDone();
         testRunner.showWebInspector();
     }
+    // This test enumerates all resources currently registered, potentially
+    // including ones no longer reachable, but not yet garbage collected
+    // and finalized.
+    //
+    // To ensure stable test output, perform a GC right here to flush out
+    // the finalizable resources.
+    gc();
     runTest();
 }