Create FrameNavigationEntries for manual subframe navigations.

content/browser/frame_host/navigation_entry_impl.h

Index: content/browser/frame_host/navigation_entry_impl.h
diff --git a/content/browser/frame_host/navigation_entry_impl.h b/content/browser/frame_host/navigation_entry_impl.h
index 646a0fb5223010a87eacedc69406ccbac7a0fe10..a5ce6fcf9f11657bf8155682a84d3f81c8953156 100644
--- a/content/browser/frame_host/navigation_entry_impl.h
+++ b/content/browser/frame_host/navigation_entry_impl.h
@@ -28,8 +28,8 @@ class CONTENT_EXPORT NavigationEntryImpl
     : public NON_EXPORTED_BASE(NavigationEntry) {
  public:
   // Represents a tree of FrameNavigationEntries that make up this joint session
-  // history item.  The tree currently only tracks the main frame.
-  // TODO(creis): Populate the tree with subframe entries in --site-per-process.
+  // history item.  The tree currently only tracks the main frame by default,
+  // and is populated with subframe nodes in --site-per-process mode.
   struct TreeNode {
     TreeNode(FrameNavigationEntry* frame_entry);
     ~TreeNode();
@@ -37,12 +37,16 @@ class CONTENT_EXPORT NavigationEntryImpl
     // Returns whether this TreeNode corresponds to |frame_tree_node|.
     bool MatchesFrame(FrameTreeNode* frame_tree_node) const;
 
-    // Returns a deep copy of the tree with copies of each node's
-    // FrameNavigationEntries.  We do not yet share FrameNavigationEntries
-    // across trees.
+    // Recursively makes a deep copy of TreeNode with copies of each of the
+    // FrameNavigationEntries in the subtree.  Replaces the TreeNode
+    // corresponding to |frame_tree_node| (and all of its children) with a new
+    // TreeNode for |frame_navigation_entry|.  Pass nullptr for both parameters
+    // to make a complete clone.
     // TODO(creis): For --site-per-process, share FrameNavigationEntries between
     // NavigationEntries of the same tab.
-    TreeNode* Clone() const;
+    scoped_ptr<TreeNode> CloneAndReplace(
+        FrameTreeNode* frame_tree_node,
+        FrameNavigationEntry* frame_navigation_entry) const;
 
     // Ref counted pointer that keeps the FrameNavigationEntry alive as long as
     // it is needed by this node's NavigationEntry.
@@ -124,11 +128,16 @@ class CONTENT_EXPORT NavigationEntryImpl
   // Creates a copy of this NavigationEntryImpl that can be modified
   // independently from the original.  Does not copy any value that would be
   // cleared in ResetForCommit.
+  NavigationEntryImpl* Clone() const;
+
+  // Like |Clone|, but replaces the FrameNavigationEntry corresponding to
+  // |frame_tree_node| (and all its children) with |frame_entry|.
   // TODO(creis): Once we start sharing FrameNavigationEntries between
   // NavigationEntryImpls, we will need to support two versions of Clone: one
   // that shares the existing FrameNavigationEntries (for use within the same
   // tab) and one that draws them from a different pool (for use in a new tab).
-  NavigationEntryImpl* Clone() const;
+  NavigationEntryImpl* CloneAndReplace(FrameTreeNode* frame_tree_node,
+                                       FrameNavigationEntry* frame_entry) const;
 
   // Helper functions to construct NavigationParameters for a navigation to this
   // NavigationEntry.