Move URLLoaderClientImpl to a separate file

content/child/url_response_body_consumer.h

Index: content/child/url_response_body_consumer.h
diff --git a/content/child/url_response_body_consumer.h b/content/child/url_response_body_consumer.h
index 09a988bdd556bf4db73217dafb9b0e02dc2979aa..1947cb66b1eb7d9efc552fe5527273d86968f3bb 100644
--- a/content/child/url_response_body_consumer.h
+++ b/content/child/url_response_body_consumer.h
@@ -51,6 +51,9 @@ class CONTENT_EXPORT URLResponseBodyConsumer final
   // cancelled or done.
   void Cancel();
 
+  void SetDefersLoading();
+  void UnsetDefersLoading();
+
  private:
   friend class base::RefCounted<URLResponseBodyConsumer>;
   ~URLResponseBodyConsumer();
@@ -71,6 +74,7 @@ class CONTENT_EXPORT URLResponseBodyConsumer final
   bool has_received_completion_ = false;
   bool has_been_cancelled_ = false;
   bool has_seen_end_of_data_;
+  bool is_deferred_ = false;
   bool is_in_on_readable_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(URLResponseBodyConsumer);