Revert of Ensure BrowserThread::CurrentlyOn is correct through MessageLoop teardown

content/browser/browser_thread_unittest.cc

Index: content/browser/browser_thread_unittest.cc
diff --git a/content/browser/browser_thread_unittest.cc b/content/browser/browser_thread_unittest.cc
index 0538819fa3d3bcecfb49604f1f679a9a83b99c70..f3f37952ff73ea072dfd12e08bb9b0ff08bbaa18 100644
--- a/content/browser/browser_thread_unittest.cc
+++ b/content/browser/browser_thread_unittest.cc
@@ -7,11 +7,9 @@
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "base/single_thread_task_runner.h"
-#include "base/threading/thread_task_runner_handle.h"
 #include "content/browser/browser_thread_impl.h"
 #include "content/public/test/test_browser_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -27,10 +25,6 @@
                                   base::MessageLoop::QuitWhenIdleClosure());
   }
 
-  void StopFileThread() {
-    file_thread_->Stop();
-  }
-
  protected:
   void SetUp() override {
     ui_thread_.reset(new BrowserThreadImpl(BrowserThread::UI));
@@ -41,7 +35,7 @@
 
   void TearDown() override {
     ui_thread_->Stop();
-    StopFileThread();
+    file_thread_->Stop();
   }
 
   static void BasicFunction(base::MessageLoop* message_loop) {
@@ -76,44 +70,6 @@
   // It's kind of ugly to make this mutable - solely so we can post the Quit
   // Task from Release(). This should be fixed.
   mutable base::MessageLoop loop_;
-};
-
-class FileThreadDestructionObserver
-    : public base::MessageLoop::DestructionObserver {
- public:
-  explicit FileThreadDestructionObserver(bool* did_shutdown,
-                                         const base::Closure& callback)
-      : callback_task_runner_(base::ThreadTaskRunnerHandle::Get()),
-        callback_(callback),
-        file_task_runner_(
-            BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE)),
-        did_shutdown_(did_shutdown) {
-    BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE)->PostTask(
-        FROM_HERE, base::Bind(&Watch, this));
-  }
-
- private:
-  static void Watch(FileThreadDestructionObserver* observer) {
-    base::MessageLoop::current()->AddDestructionObserver(observer);
-  }
-
-  // base::MessageLoop::DestructionObserver:
-  void WillDestroyCurrentMessageLoop() override {
-    // Ensure that even during MessageLoop teardown the BrowserThread ID is
-    // correctly associated with this thread and the BrowserThreadTaskRunner
-    // knows it's on the right thread.
-    EXPECT_TRUE(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-    EXPECT_TRUE(file_task_runner_->BelongsToCurrentThread());
-
-    base::MessageLoop::current()->RemoveDestructionObserver(this);
-    *did_shutdown_ = true;
-    callback_task_runner_->PostTask(FROM_HERE, callback_);
-  }
-
-  const scoped_refptr<base::SingleThreadTaskRunner> callback_task_runner_;
-  const base::Closure callback_;
-  const scoped_refptr<base::SingleThreadTaskRunner> file_task_runner_;
-  bool* did_shutdown_;
 };
 
 TEST_F(BrowserThreadTest, PostTask) {
@@ -162,16 +118,4 @@
   base::RunLoop().Run();
 }
 
-TEST_F(BrowserThreadTest, RunsTasksOnCurrentThreadDuringShutdown) {
-  bool did_shutdown = false;
-  base::RunLoop loop;
-  FileThreadDestructionObserver observer(&did_shutdown, loop.QuitClosure());
-  base::ThreadTaskRunnerHandle::Get()->PostTask(
-      FROM_HERE,
-      base::Bind(&BrowserThreadTest::StopFileThread, base::Unretained(this)));
-  loop.Run();
-
-  EXPECT_TRUE(did_shutdown);
-}
-
 }  // namespace content