Move MimeTypeResourceHandler before ThrottlingResourceHandler

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 50153c6706bfa0951f8506161aa063702a7069b1..ab3ebb5d4c5c7d6de73bebd3f701957aeaa6c27f 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -55,6 +55,7 @@
 #include "content/browser/loader/navigation_url_loader_impl_core.h"
 #include "content/browser/loader/power_save_block_resource_throttle.h"
 #include "content/browser/loader/redirect_to_file_resource_handler.h"
+#include "content/browser/loader/replacing_resource_handler.h"
 #include "content/browser/loader/resource_message_filter.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/browser/loader/stream_resource_handler.h"
@@ -1725,9 +1726,11 @@ ResourceDispatcherHostImpl::AddStandardHandlers(
 #if defined(ENABLE_PLUGINS)
   plugin_service = PluginService::GetInstance();
 #endif
-  // Insert a buffered event handler before the actual one.
-  handler.reset(new MimeTypeResourceHandler(std::move(handler), this,
-                                            plugin_service, request));
+
+  // The ReplacingResourceThrottle will replace its next handler with an
+  // appropriate one based on the MIME type of the response if needed.

[mmenke, 2016/06/09 18:18:42]

Maybe mention that this must be at the end of the chain, just before |handler|?

[clamy, 2016/06/21 16:14:15]

Done.

+  handler.reset(new ReplacingResourceHandler(std::move(handler), this,
+                                             plugin_service, request));
 
   ScopedVector<ResourceThrottle> throttles;
 
@@ -1759,6 +1762,9 @@ ResourceDispatcherHostImpl::AddStandardHandlers(
   handler.reset(new ThrottlingResourceHandler(std::move(handler), request,
                                               std::move(throttles)));
 
+  // Insert a buffered event handler to sniff the mime type first.
+  handler.reset(new MimeTypeResourceHandler(std::move(handler), request));
+
   return handler;
 }