Forwarding POST body into renderer after a cross-site transfer.

content/browser/frame_host/navigator_impl.h

Index: content/browser/frame_host/navigator_impl.h
diff --git a/content/browser/frame_host/navigator_impl.h b/content/browser/frame_host/navigator_impl.h
index d760f7ce9da3df1cc80b81290fc3feb792d5fff5..82a995b05f30ffd018542a987bd7d656eb5e7047 100644
--- a/content/browser/frame_host/navigator_impl.h
+++ b/content/browser/frame_host/navigator_impl.h
@@ -24,6 +24,7 @@ namespace content {
 class NavigationControllerImpl;
 class NavigatorDelegate;
 class NavigatorTest;
+class ResourceRequestBody;
 struct LoadCommittedDetails;
 
 // This class is an implementation of Navigator, responsible for managing
@@ -69,14 +70,17 @@ class CONTENT_EXPORT NavigatorImpl : public Navigator {
                       WindowOpenDisposition disposition,
                       bool should_replace_current_entry,
                       bool user_gesture) override;
-  void RequestTransferURL(RenderFrameHostImpl* render_frame_host,
-                          const GURL& url,
-                          SiteInstance* source_site_instance,
-                          const std::vector<GURL>& redirect_chain,
-                          const Referrer& referrer,
-                          ui::PageTransition page_transition,
-                          const GlobalRequestID& transferred_global_request_id,
-                          bool should_replace_current_entry) override;
+  void RequestTransferURL(
+      RenderFrameHostImpl* render_frame_host,
+      const GURL& url,
+      SiteInstance* source_site_instance,
+      const std::vector<GURL>& redirect_chain,
+      const Referrer& referrer,
+      ui::PageTransition page_transition,
+      const GlobalRequestID& transferred_global_request_id,
+      bool should_replace_current_entry,
+      const std::string& method,
+      const scoped_refptr<ResourceRequestBody>& post_body) override;

[clamy, 2016/05/23 15:32:28]

A const scoped_refptr<...>& looks very weird. Do we have other instances of this
in the codebase?

[Łukasz Anforowicz, 2016/05/23 16:25:10]

2286 hits in code search :-) [1]

This pattern avoids increasing/decreasing ref-count for every frame on the
callstack (i.e. each function takes a const-ref, and the final called function
copy-assigns or copy-constructs into a scoped_refptr - only the final copy
causes a refcount bump).

I see that the style guide now asks to just declare "scoped_ptr<T>" and the
caller can decide whether to transfer or increase the ref-count.  I am not sure
if I buy that argument (caller might want to keep its ref-count, but
intermediate chain of functions on the callstack might not + even the final
caller might or might not take refcount depending on other things).

BTW: If function doesn't ever take ref-count, then it should take "const T&" as
discussed in [2].  But this is not such situation - we are eventually going to
pass the refcount to the IPC message payload.

Let's leave this as-is, unless //content OWNERs complain?

[1]
https://code.google.com/p/chromium/codesearch#search/&q=%22const%20scoped_ref...

[2]
https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/noOt34XStEU

   void OnBeforeUnloadACK(FrameTreeNode* frame_tree_node, bool proceed) override;
   void OnBeginNavigation(FrameTreeNode* frame_tree_node,
                          const CommonNavigationParams& common_params,
@@ -106,7 +110,8 @@ class CONTENT_EXPORT NavigatorImpl : public Navigator {
                        const NavigationEntryImpl& entry,
                        NavigationController::ReloadType reload_type,
                        bool is_same_document_history_load,
-                       bool is_pending_entry);
+                       bool is_pending_entry,
+                       const scoped_refptr<ResourceRequestBody>& post_body);
 
   bool ShouldAssignSiteForURL(const GURL& url);