Have content/ create and destroy its own threads.

content/test/test_browser_thread.h

Index: content/test/test_browser_thread.h
diff --git a/content/test/test_browser_thread.h b/content/test/test_browser_thread.h
index 5d3439e363f9d313df61a1ef561aa1327701c33c..9466ae2e1e806a8bb236ee1bc4c46e7a08e1af01 100644
--- a/content/test/test_browser_thread.h
+++ b/content/test/test_browser_thread.h
@@ -18,7 +18,7 @@ class Thread;
 
 namespace content {
 
-class BrowserThreadImpl;
+class TestBrowserThreadImpl;
 
 // A BrowserThread for unit tests; this lets unit tests in chrome/
 // create BrowserThread instances.
@@ -49,8 +49,12 @@ class TestBrowserThread {
   // in new tests.
   base::Thread* DeprecatedGetThreadObject();
 
+  // Sets the message loop to use for the thread. This should not be
+  // used in new tests.
+  void DeprecatedSetMessageLoop(MessageLoop* loop);
+
  private:
-  scoped_ptr<BrowserThreadImpl> impl_;
+  scoped_ptr<TestBrowserThreadImpl> impl_;
 
   DISALLOW_COPY_AND_ASSIGN(TestBrowserThread);
 };