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

content/browser/frame_host/navigator_impl.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_NAVIGATOR_IMPL_H_
 #define CONTENT_BROWSER_FRAME_HOST_NAVIGATOR_IMPL_H_
 
 #include <memory>
 
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 #include "content/browser/frame_host/navigation_controller_impl.h"
 #include "content/browser/frame_host/navigator.h"
 #include "content/common/content_export.h"
 #include "content/common/navigation_params.h"
 #include "url/gurl.h"
 
 class GURL;
 
 namespace content {
 
 class NavigationControllerImpl;
 class NavigatorDelegate;
 class NavigatorTest;
+class ResourceRequestBody;
 struct LoadCommittedDetails;
 
 // This class is an implementation of Navigator, responsible for managing
 // navigations in regular browser tabs.
 class CONTENT_EXPORT NavigatorImpl : public Navigator {
  public:
   NavigatorImpl(NavigationControllerImpl* navigation_controller,
                 NavigatorDelegate* delegate);
 
   static void CheckWebUIRendererDoesNotDisplayNormalURL(
@@ skipping 25 matching lines @@
                               bool is_same_document_history_load) override;
   bool NavigateNewChildFrame(RenderFrameHostImpl* render_frame_host,
                              const std::string& unique_name) override;
   void RequestOpenURL(RenderFrameHostImpl* render_frame_host,
                       const GURL& url,
                       SiteInstance* source_site_instance,
                       const Referrer& referrer,
                       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,
                          const BeginNavigationParams& begin_params) override;
   void FailedNavigation(FrameTreeNode* frame_tree_node,
                         bool has_stale_copy_in_cache,
                         int error_code) override;
   void LogResourceRequestTime(base::TimeTicks timestamp,
                               const GURL& url) override;
   void LogBeforeUnloadTime(
       const base::TimeTicks& renderer_before_unload_start_time,
       const base::TimeTicks& renderer_before_unload_end_time) override;
   void CancelNavigation(FrameTreeNode* frame_tree_node) override;
 
  private:
   // Holds data used to track browser side navigation metrics.
   struct NavigationMetricsData;
 
   friend class NavigatorTestWithBrowserSideNavigation;
   ~NavigatorImpl() override;
 
   // Navigates to the given entry, which might be the pending entry (if
   // |is_pending_entry| is true).  Private because all callers should use either
   // NavigateToPendingEntry or NavigateToNewChildFrame.
   bool NavigateToEntry(FrameTreeNode* frame_tree_node,
                        const FrameNavigationEntry& frame_entry,
                        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);
 
   // PlzNavigate: if needed, sends a BeforeUnload IPC to the renderer to ask it
   // to execute the beforeUnload event. Otherwise, the navigation request will
   // be started.
   void RequestNavigation(FrameTreeNode* frame_tree_node,
                          const GURL& dest_url,
                          const Referrer& dest_referrer,
                          const FrameNavigationEntry& frame_entry,
@@ skipping 30 matching lines @@
   NavigatorDelegate* delegate_;
 
   std::unique_ptr<NavigatorImpl::NavigationMetricsData> navigation_data_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigatorImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_NAVIGATOR_IMPL_H_