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_;

[ananta, 2017/03/29 19:41:04]

This change was required to ensure that the thread bundle gets destroyed
before the other members of this class like ResourceDispatcherHostImpl, etc. Not
doing this causes dchecks to fire in the code due to a null LoaderGlobals
instance.

   LoaderDelegateImpl loader_deleate_;
   ResourceDispatcherHostImpl rdh_;
   std::unique_ptr<TestBrowserContext> browser_context_;