Reduce/remove usage of BrowserThread in content/browser/loader.

content/browser/loader/url_loader_factory_impl_unittest.cc

Index: content/browser/loader/url_loader_factory_impl_unittest.cc
diff --git a/content/browser/loader/url_loader_factory_impl_unittest.cc b/content/browser/loader/url_loader_factory_impl_unittest.cc
index 007dca1e4dc48f451a32610ebb7cac9b3a10ba68..ad3433aebadfd4598bf147019d3576d7c44ccac0 100644
--- a/content/browser/loader/url_loader_factory_impl_unittest.cc
+++ b/content/browser/loader/url_loader_factory_impl_unittest.cc
@@ -81,7 +81,8 @@ class RejectingResourceDispatcherHostDelegate final
 class URLLoaderFactoryImplTest : public ::testing::TestWithParam<size_t> {
  public:
   URLLoaderFactoryImplTest()
-      : thread_bundle_(TestBrowserThreadBundle::IO_MAINLOOP),
+      : thread_bundle_(
+            new TestBrowserThreadBundle(TestBrowserThreadBundle::IO_MAINLOOP)),
         browser_context_(new TestBrowserContext()),
         resource_message_filter_(new ResourceMessageFilter(
             kChildId,
@@ -120,6 +121,7 @@ class URLLoaderFactoryImplTest : public ::testing::TestWithParam<size_t> {
     base::RunLoop().RunUntilIdle();
     MojoAsyncResourceHandler::SetAllocationSizeForTesting(
         MojoAsyncResourceHandler::kDefaultAllocationSize);
+    thread_bundle_.reset(nullptr);
   }
 
   void GetContexts(ResourceType resource_type,
@@ -130,7 +132,7 @@ class URLLoaderFactoryImplTest : public ::testing::TestWithParam<size_t> {
         browser_context_->GetResourceContext()->GetRequestContext();
   }
 
-  TestBrowserThreadBundle thread_bundle_;
+  std::unique_ptr<TestBrowserThreadBundle> thread_bundle_;
   LoaderDelegateImpl loader_deleate_;
   ResourceDispatcherHostImpl rdh_;
   std::unique_ptr<TestBrowserContext> browser_context_;