scheduler: Maintain a constant enqueue order for every task

content/browser/devtools/protocol/devtools_protocol_browsertest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/base64.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 1349 matching lines @@
 }
 
 IN_PROC_BROWSER_TEST_F(DevToolsProtocolTest, VirtualTimeTest) {
   NavigateToURLBlockUntilNavigationsComplete(shell(), GURL("about:blank"), 1);
   Attach();
 
   std::unique_ptr<base::DictionaryValue> params(new base::DictionaryValue());
   params->SetString("policy", "pause");
   SendCommand("Emulation.setVirtualTimePolicy", std::move(params), true);
 
-  // TODO(scheduler-dev): Revisit timing when we have strict ordering
-  // guarantees.
   params.reset(new base::DictionaryValue());
   params->SetString("expression",
                     "setTimeout(function(){console.log('before')}, 1000);"
-                    "setTimeout(function(){console.log('after')}, 1002);");
+                    "setTimeout(function(){console.log('after')}, 1001);");
   SendCommand("Runtime.evaluate", std::move(params), true);
 
   // Let virtual time advance for one second.
   params.reset(new base::DictionaryValue());
   params->SetString("policy", "advance");
-  params->SetInteger("budget", 1001);
+  params->SetInteger("budget", 1000);
   SendCommand("Emulation.setVirtualTimePolicy", std::move(params), true);
 
   WaitForNotification("Emulation.virtualTimeBudgetExpired");
 
   params.reset(new base::DictionaryValue());
   params->SetString("expression", "console.log('done')");
   SendCommand("Runtime.evaluate", std::move(params), true);
 
   // The second timer shold not fire.
   EXPECT_THAT(console_messages_, ElementsAre("before", "done"));
@@ skipping 411 matching lines @@
       EXPECT_EQ("polyglottal", value);
       found++;
     } else {
       FAIL();
     }
   }
   EXPECT_EQ(2u, found);
 }
 
 }  // namespace content