Create FrameNavigationEntries for manual subframe navigations.

content/browser/frame_host/navigation_entry_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_NAVIGATION_ENTRY_IMPL_H_
 #define CONTENT_BROWSER_FRAME_HOST_NAVIGATION_ENTRY_IMPL_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_vector.h"
@@ skipping 10 matching lines @@
 
 namespace content {
 struct CommonNavigationParams;
 struct RequestNavigationParams;
 struct StartNavigationParams;
 
 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();
 
+    // 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.
+    // FrameNavigationEntries.  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 for a complete clone.

[Avi (use Gerrit), 2015/05/19 16:34:13]

I'm pondering this comment.

1. "with copies of each node's FNEs". We're not making copies, though, we're
sharing the the FNEs with ref-counted pointers, right?

2. "of the tree" meaning the tree rooted at this entry?

[Charlie Reis, 2015/05/19 17:59:24]

We're not sharing FNEs just yet (hence the TODO below).  I decided to postpone
that to another CL since it affects cloning tabs, session restore, etc.  Easier
to just have each tree have its own set of FNEs for the moment, and then we can
start sharing them.
Agreed, this part is confusing, since the comment is on TreeNode but is phrased
as the whole tree.  I've rephrased it.

+    //
     // TODO(creis): For --site-per-process, share FrameNavigationEntries between
     // NavigationEntries of the same tab.
-    TreeNode* Clone() const;
+    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.
     scoped_refptr<FrameNavigationEntry> frame_entry;
 
     // List of child TreeNodes, which will be deleted when this node is.
     ScopedVector<TreeNode> children;
   };
 
   static NavigationEntryImpl* FromNavigationEntry(NavigationEntry* entry);
@@ skipping 59 matching lines @@
   void ClearExtraData(const std::string& key) override;
   void SetHttpStatusCode(int http_status_code) override;
   int GetHttpStatusCode() const override;
   void SetRedirectChain(const std::vector<GURL>& redirects) override;
   const std::vector<GURL>& GetRedirectChain() const override;
   bool IsRestored() const override;
 
   // 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.
   CommonNavigationParams ConstructCommonNavigationParams(
       FrameMsg_Navigate_Type::Value navigation_type) const;
   StartNavigationParams ConstructStartNavigationParams() const;
   RequestNavigationParams ConstructRequestNavigationParams(
       base::TimeTicks navigation_start,
       bool intended_as_new_entry,
       int pending_offset_to_send,
@@ skipping 295 matching lines @@
   // persisted, unless specific data is taken out/put back in at save/restore
   // time (see TabNavigation for an example of this).
   std::map<std::string, base::string16> extra_data_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigationEntryImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_NAVIGATION_ENTRY_IMPL_H_