Destroy all Singletons and LazyInstances between each test.

base/test/test_suite.h

Index: base/test/test_suite.h
diff --git a/base/test/test_suite.h b/base/test/test_suite.h
index 9f139ed0f648d0b067a7135cf98ff5878398beaa..1b18dcbdae163eae9fdda9f3f716ac86593774f1 100644
--- a/base/test/test_suite.h
+++ b/base/test/test_suite.h
@@ -59,6 +59,11 @@ class TestSuite {
   virtual void Initialize();
   virtual void Shutdown();
 
+  // Sets up a TestEventListener to shadow the at_exit_manager_ between each
+  // individual test. Broken test suites can override this method to disable
+  // this behavior until they can be fixed.
+  virtual void EnableSingletonTestIsolation();

[jam, 2013/05/07 18:09:57]

i highly suggest not adding this method, i.e. not having a way for tests to get
out of this correct mode.

when we add things like ScopedAllowIO, they  just get misused

[Robert Sesek, 2013/05/07 18:12:29]

Good point. Done.

+
   // Make sure that we setup an AtExitManager so Singleton objects will be
   // destroyed.
   scoped_ptr<base::AtExitManager> at_exit_manager_;