Add Clone and disallow copy construction for NavigationEntryImpl.

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/time/time.h"
@@ skipping 72 matching lines @@
                     const base::string16& data) override;
   bool GetExtraData(const std::string& key,
                     base::string16* data) const override;
   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.
+  // 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).

[Avi (use Gerrit), 2015/03/12 16:59:19]

Does this version of Clone have one of those behaviors? If you can decide what
those two Clones will be called
(CloneForSameController/CloneForDifferentController or maybe
CloneForController(NavController*) perhaps you might want to name it like that
now.

[Charlie Reis, 2015/03/12 17:07:43]

Yeah, I hadn't thought closely about whether to have two methods or give a
parameter, since I'm not sure what we'll need to pass in yet.  (So far
NavigationEntry doesn't depend on NavigationController at all, so it might be
nice to pass in some kind of mutable set of FrameNavigationEntries.)

At the moment, there's no difference between the behaviors since we don't have
shared entries.  Let's wait on the new name until there's a behavior difference.

+  NavigationEntryImpl* Clone() const;
+
   // Once a navigation entry is committed, we should no longer track several
   // pieces of non-persisted state, as documented on the members below.
   void ResetForCommit();
 
   void set_unique_id(int unique_id) {
     unique_id_ = unique_id;
   }
 
   // The SiteInstance represents which pages must share processes. This is a
   // reference counted pointer to a shared SiteInstance.
@@ skipping 135 matching lines @@
     intent_received_timestamp_ = intent_received_timestamp;
   }
 #endif
 
  private:
   // WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
   // Session/Tab restore save portions of this class so that it can be recreated
   // later. If you add a new field that needs to be persisted you'll have to
   // update SessionService/TabRestoreService and Android WebView
   // state_serializer.cc appropriately.
+  // For all new fields, update |Clone| and possibly |ResetForCommit|.
   // WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
 
   // The FrameNavigationEntry for the main frame.
   // TODO(creis): Make this a tree with nodes for each frame in the page.
   FrameNavigationEntry frame_entry_;
 
   // See the accessors above for descriptions.
   int unique_id_;
   // TODO(creis): Persist bindings_. http://crbug.com/173672.
   int bindings_;
@@ skipping 104 matching lines @@
   // The time at which Chrome received the Android Intent that triggered this
   // URL load operation. Reset at commit and not persisted.
   base::TimeTicks intent_received_timestamp_;
 #endif
 
   // Used to store extra data to support browser features. This member is not
   // 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_;
 
-  // Copy and assignment is explicitly allowed for this class.
+  DISALLOW_COPY_AND_ASSIGN(NavigationEntryImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_NAVIGATION_ENTRY_IMPL_H_