Revert of Support base::test::ScopedTaskEnvironment and content::TestBrowserThreadBundle in the same scope.

content/public/test/test_browser_thread_bundle.h

Index: content/public/test/test_browser_thread_bundle.h
diff --git a/content/public/test/test_browser_thread_bundle.h b/content/public/test/test_browser_thread_bundle.h
index 7298d0e37af2ee2c3c43744bffc1712e0ccf0268..15cdba8f5c6b350876bfb172fe04a15de5dac492 100644
--- a/content/public/test/test_browser_thread_bundle.h
+++ b/content/public/test/test_browser_thread_bundle.h
@@ -53,15 +53,6 @@
 //
 // DONT_CREATE_THREADS should only be used when the options specify at least
 // one real thread other than the main thread.
-//
-// TestBrowserThreadBundle may be instantiated in a scope where there is already
-// a base::test::ScopedTaskEnvironment. In that case, it will use the
-// MessageLoop and the TaskScheduler provided by this
-// base::test::ScopedTaskEnvironment instead of creating its own. The ability to
-// have a base::test::ScopedTaskEnvironment and a TestBrowserThreadBundle in the
-// same scope is useful when a fixture that inherits from a fixture that
-// provides a base::test::ScopedTaskEnvironment needs to add support for browser
-// threads.
 
 #ifndef CONTENT_PUBLIC_TEST_TEST_BROWSER_THREAD_BUNDLE_H_
 #define CONTENT_PUBLIC_TEST_TEST_BROWSER_THREAD_BUNDLE_H_