Do not sniff mime type for fetch() requests

content/browser/loader/resource_dispatcher_host_impl.cc

Index: content/browser/loader/resource_dispatcher_host_impl.cc
diff --git a/content/browser/loader/resource_dispatcher_host_impl.cc b/content/browser/loader/resource_dispatcher_host_impl.cc
index 8cd54dbb292f4a714de9c2f04673d12fdb56f68b..181828a05a512274762df34daeb252c64b8a983d 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -1691,11 +1691,12 @@ ResourceDispatcherHostImpl::AddStandardHandlers(
 #endif
 
   // Insert a buffered event handler to sniff the mime type.
-  // Note: all ResourceHandler following the MimeSniffingResourceHandler should
-  // expect OnWillRead to be called *before* OnResponseStarted as part of the
-  // mime sniffing process.
+  // Note: all ResourceHandler following the MimeSniffingResourceHandler
+  // should expect OnWillRead to be called *before* OnResponseStarted as
+  // part of the mime sniffing process.
   handler.reset(new MimeSniffingResourceHandler(
-      std::move(handler), this, plugin_service, intercepting_handler, request));
+      std::move(handler), this, plugin_service, intercepting_handler, request,
+      fetch_request_context_type));
 
   // Add the pre mime sniffing throttles.
   handler.reset(new ThrottlingResourceHandler(