Remove InProcessBrowserTest::SetUpOnMainThread() calls.

chrome/browser/chromeos/login/mixin_based_browser_test.cc

 // Copyright (c) 2014 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 "chrome/browser/chromeos/login/mixin_based_browser_test.h"
 
 #include <utility>
 
 #include "base/containers/adapters.h"
 
@@ skipping 18 matching lines @@
   for (const auto& mixin : mixins_)
     mixin->SetUpInProcessBrowserTestFixture();
 
   InProcessBrowserTest::SetUpInProcessBrowserTestFixture();
 }
 
 void MixinBasedBrowserTest::SetUpOnMainThread() {
   setup_was_launched_ = true;
   for (const auto& mixin : mixins_)
     mixin->SetUpOnMainThread();
-
-  InProcessBrowserTest::SetUpOnMainThread();
 }
 
 void MixinBasedBrowserTest::TearDownOnMainThread() {
   InProcessBrowserTest::TearDownOnMainThread();
   for (const auto& mixin : base::Reversed(mixins_))
     mixin->TearDownInProcessBrowserTestFixture();
 }
 void MixinBasedBrowserTest::TearDownInProcessBrowserTestFixture() {
   InProcessBrowserTest::TearDownInProcessBrowserTestFixture();
   for (const auto& mixin : base::Reversed(mixins_))
     mixin->TearDownInProcessBrowserTestFixture();
 }
 
 void MixinBasedBrowserTest::AddMixin(std::unique_ptr<Mixin> mixin) {
   CHECK(!setup_was_launched_)
       << "You are trying to add a mixin after setting up has already started.";
   mixins_.push_back(std::move(mixin));
 }
 
 }  // namespace chromeos