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

content/browser/loader/resource_message_filter.h

Index: content/browser/loader/resource_message_filter.h
diff --git a/content/browser/loader/resource_message_filter.h b/content/browser/loader/resource_message_filter.h
index 45c4e2b74b90fe0d5bec4cb23dc0e1e568a1fcca..da440131a26d3d5176345e7de29b6d73139de7f9 100644
--- a/content/browser/loader/resource_message_filter.h
+++ b/content/browser/loader/resource_message_filter.h
@@ -12,11 +12,11 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/sequenced_task_runner_helpers.h"
+#include "base/single_thread_task_runner.h"
 #include "content/common/content_export.h"
 #include "content/common/url_loader_factory.mojom.h"
 #include "content/public/browser/browser_associated_interface.h"
 #include "content/public/browser/browser_message_filter.h"
-#include "content/public/browser/browser_thread.h"
 #include "content/public/common/resource_type.h"
 
 namespace storage {
@@ -53,12 +53,14 @@ class CONTENT_EXPORT ResourceMessageFilter
   // |service_worker_context| may be nullptr in unittests.
   // InitializeForTest() needs to be manually called for unittests where
   // OnFilterAdded() would not otherwise be called.
-  ResourceMessageFilter(int child_id,
-                        ChromeAppCacheService* appcache_service,
-                        ChromeBlobStorageContext* blob_storage_context,
-                        storage::FileSystemContext* file_system_context,
-                        ServiceWorkerContextWrapper* service_worker_context,
-                        const GetContextsCallback& get_contexts_callback);
+  ResourceMessageFilter(
+      int child_id,
+      ChromeAppCacheService* appcache_service,
+      ChromeBlobStorageContext* blob_storage_context,
+      storage::FileSystemContext* file_system_context,
+      ServiceWorkerContextWrapper* service_worker_context,
+      const GetContextsCallback& get_contexts_callback,
+      const scoped_refptr<base::SingleThreadTaskRunner>& io_thread_runner);
 
   // BrowserMessageFilter implementation.
   void OnFilterAdded(IPC::Channel* channel) override;
@@ -89,7 +91,6 @@ class CONTENT_EXPORT ResourceMessageFilter
   ~ResourceMessageFilter() override;
 
  private:
-  friend struct BrowserThread::DeleteOnThread<BrowserThread::IO>;
   friend class base::DeleteHelper<ResourceMessageFilter>;
 
   // Initializes the weak pointer of this filter in |requester_info_|.
@@ -98,6 +99,9 @@ class CONTENT_EXPORT ResourceMessageFilter
   bool is_channel_closed_;
   scoped_refptr<ResourceRequesterInfo> requester_info_;
 
+  // Task runner for the IO thead.
+  scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner_;
+
   // This must come last to make sure weak pointers are invalidated first.
   base::WeakPtrFactory<ResourceMessageFilter> weak_ptr_factory_;