Expose Thread::using_external_message_loop() to subclasses.

base/threading/thread_unittest.cc

 // Copyright (c) 2012 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 "base/threading/thread.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <vector>
@@ skipping 468 matching lines @@
 // underlying thread (instead its messages can be processed by a RunLoop on the
 // stack).
 class ExternalMessageLoopThread : public Thread {
  public:
   ExternalMessageLoopThread() : Thread("ExternalMessageLoopThread") {}
 
   ~ExternalMessageLoopThread() override { Stop(); }
 
   void InstallMessageLoop() { SetMessageLoop(&external_message_loop_); }
 
+  void VerifyUsingExternalMessageLoop(
+      bool expected_using_external_message_loop) {
+    EXPECT_EQ(expected_using_external_message_loop,
+              using_external_message_loop());
+  }
+
  private:
   base::MessageLoop external_message_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(ExternalMessageLoopThread);
 };
 
 }  // namespace
 
 TEST_F(ThreadTest, ExternalMessageLoop) {
   ExternalMessageLoopThread a;
   EXPECT_FALSE(a.message_loop());
   EXPECT_FALSE(a.IsRunning());
+  a.VerifyUsingExternalMessageLoop(false);
 
   a.InstallMessageLoop();
   EXPECT_TRUE(a.message_loop());
   EXPECT_TRUE(a.IsRunning());
+  a.VerifyUsingExternalMessageLoop(true);
 
   bool ran = false;
   a.task_runner()->PostTask(
       FROM_HERE, base::Bind([](bool* toggled) { *toggled = true; }, &ran));
   base::RunLoop().RunUntilIdle();
   EXPECT_TRUE(ran);
 
   a.Stop();
   EXPECT_FALSE(a.message_loop());
   EXPECT_FALSE(a.IsRunning());
+  a.VerifyUsingExternalMessageLoop(true);
 
   // Confirm that running any remaining tasks posted from Stop() goes smoothly
   // (e.g. https://codereview.chromium.org/2135413003/#ps300001 crashed if
   // StopSoon() posted Thread::ThreadQuitHelper() while |run_loop_| was null).
   base::RunLoop().RunUntilIdle();
 }