DRAFT CL: Add FrameNavigationEntry and track subframe session histories.

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 bf075ff6879a430619a1bcbdbed1f7e6f94eccaf..7e2c78be795caa8cb255a3506241d4db137d8a3b 100644
--- a/content/browser/frame_host/navigator_impl.h
+++ b/content/browser/frame_host/navigator_impl.h
@@ -52,6 +52,7 @@ class CONTENT_EXPORT NavigatorImpl : public Navigator {
                        input_params) override;
   bool NavigateToPendingEntry(
       FrameTreeNode* frame_tree_node,
+      const FrameNavigationEntry& frame_nav_entry,
       NavigationController::ReloadType reload_type) override;
   void RequestOpenURL(RenderFrameHostImpl* render_frame_host,
                       const GURL& url,
@@ -102,6 +103,7 @@ class CONTENT_EXPORT NavigatorImpl : public Navigator {
   // because all callers should use NavigateToPendingEntry.
   bool NavigateToEntry(
       FrameTreeNode* frame_tree_node,
+      const FrameNavigationEntry& frame_nav_entry,
       const NavigationEntryImpl& entry,
       NavigationController::ReloadType reload_type);
 
@@ -115,6 +117,7 @@ class CONTENT_EXPORT NavigatorImpl : public Navigator {
   // to execute the beforeUnload event. Otherwise, the navigation request will
   // be started.
   void RequestNavigation(FrameTreeNode* frame_tree_node,
+                         const FrameNavigationEntry& frame_entry,
                          const NavigationEntryImpl& entry,
                          NavigationController::ReloadType reload_type,
                          base::TimeTicks navigation_start);