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

content/browser/loader/resource_dispatcher_host_impl.h

Index: content/browser/loader/resource_dispatcher_host_impl.h
diff --git a/content/browser/loader/resource_dispatcher_host_impl.h b/content/browser/loader/resource_dispatcher_host_impl.h
index f039aa13b1b9dc2e80ffd954a75f47e48951749c..5e1857c3de6c43fb166b0f70c731343b1f3821db 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.h
+++ b/content/browser/loader/resource_dispatcher_host_impl.h
@@ -26,6 +26,7 @@
 #include "base/observer_list.h"
 #include "base/time/time.h"
 #include "content/browser/loader/global_routing_id.h"
+#include "content/browser/loader/loader_globals.h"
 #include "content/browser/loader/resource_loader_delegate.h"
 #include "content/common/content_export.h"
 #include "content/common/url_loader.mojom.h"
@@ -91,7 +92,9 @@ class CONTENT_EXPORT ResourceDispatcherHostImpl
   // Work on moving creation of download handlers out of
   // ResourceDispatcherHostImpl.
   ResourceDispatcherHostImpl(
-      CreateDownloadHandlerIntercept download_handler_intercept);
+      CreateDownloadHandlerIntercept download_handler_intercept,
+      const scoped_refptr<base::SingleThreadTaskRunner>& main_thread_runner,
+      const scoped_refptr<base::SingleThreadTaskRunner>& io_thread_runner);
   ResourceDispatcherHostImpl();
   ~ResourceDispatcherHostImpl() override;
 
@@ -757,6 +760,9 @@ class CONTENT_EXPORT ResourceDispatcherHostImpl
   // Points to the registered download handler intercept.
   CreateDownloadHandlerIntercept create_download_handler_intercept_;
 
+  // Points to the global instance of the LoaderGlobals class.
+  std::unique_ptr<LoaderGlobals> loader_globals_;
+
   DISALLOW_COPY_AND_ASSIGN(ResourceDispatcherHostImpl);
 };