Move ownership of source SiteInstance to the FrameNavigationEntry.

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 <stdint.h>
 
 #include "base/macros.h"
@@ skipping 159 matching lines @@
       const FrameNavigationEntry& frame_entry,
       bool is_same_document_history_load,
       bool has_committed_real_load,
       bool intended_as_new_entry,
       int pending_offset_to_send,
       int current_offset_to_send,
       int current_length_to_send) 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();
+  // |frame_entry| is the FrameNavigationEntry for the frame that committed
+  // the navigation. It can be null if subframe navigation entries are not

[Charlie Reis, 2016/05/05 22:20:00]

I wish it were as simple as "if subframe navigation entries are not in use."  :)

It's also null in all the cases mentioned in https://crbug.com/608402, and
possibly others.  We probably just want to say that it can be null without
saying when, or that it's when we end up with no corresponding
FrameNavigationEntry for a commit.

[nasko, 2016/05/06 00:13:41]

Done.

+  // in use.
+  void ResetForCommit(FrameNavigationEntry* frame_entry);
 
   // Exposes the tree of FrameNavigationEntries that make up this joint session
   // history item.
   // In default Chrome, this tree only has a root node with an unshared
   // FrameNavigationEntry.  Subframes are only added to the tree if the
   // --site-per-process flag is passed.
   TreeNode* root_node() const {
     return frame_tree_.get();
   }
 
   // Finds the TreeNode associated with |frame_tree_node_id| to add or update
   // its FrameNavigationEntry.  A new FrameNavigationEntry is added if none
   // exists, or else the existing one (which might be shared with other
   // NavigationEntries) is updated with the given parameters.
   // Does nothing if there is no entry already and |url| is about:blank, since
   // that does not count as a real commit.
-  void AddOrUpdateFrameEntry(FrameTreeNode* frame_tree_node,
-                             int64_t item_sequence_number,
-                             int64_t document_sequence_number,
-                             SiteInstanceImpl* site_instance,
-                             const GURL& url,
-                             const Referrer& referrer,
-                             const PageState& page_state,
-                             const std::string& method,
-                             int64_t post_id);
+  void AddOrUpdateFrameEntry(
+      FrameTreeNode* frame_tree_node,
+      int64_t item_sequence_number,
+      int64_t document_sequence_number,
+      SiteInstanceImpl* site_instance,
+      scoped_refptr<SiteInstanceImpl> source_site_instance,
+      const GURL& url,
+      const Referrer& referrer,
+      const PageState& page_state,
+      const std::string& method,
+      int64_t post_id);
 
   // Returns the FrameNavigationEntry corresponding to |frame_tree_node|, if
   // there is one in this NavigationEntry.
   FrameNavigationEntry* GetFrameEntry(FrameTreeNode* frame_tree_node) const;
 
   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.
   //
   // Note that the SiteInstance should usually not be changed after it is set,
   // but this may happen if the NavigationEntry was cloned and needs to use a
   // different SiteInstance.
   void set_site_instance(scoped_refptr<SiteInstanceImpl> site_instance);
   SiteInstanceImpl* site_instance() const {
     return frame_tree_->frame_entry->site_instance();
   }
 
   // The |source_site_instance| is used to identify the SiteInstance of the
-  // frame that initiated the navigation.
-  void set_source_site_instance(SiteInstanceImpl* source_site_instance);
-  SiteInstanceImpl* source_site_instance() const {
-    return source_site_instance_.get();
+  // frame that initiated the navigation. It is set on the
+  // FrameNavigationEntry for the main frame.
+  void set_source_site_instance(
+      scoped_refptr<SiteInstanceImpl> source_site_instance) {
+    root_node()->frame_entry->set_source_site_instance(
+        source_site_instance.get());
   }
 
   // Remember the set of bindings granted to this NavigationEntry at the time
   // of commit, to ensure that we do not grant it additional bindings if we
   // navigate back to it in the future.  This can only be changed once.
   void SetBindings(int bindings);
   int bindings() const {
     return bindings_;
   }
 
@@ skipping 170 matching lines @@
   // page. This screenshot is displayed during an overscroll-navigation
   // gesture. |screenshot_| will be NULL when the screenshot is not available
   // (e.g. after a session restore, or if taking the screenshot of a page
   // failed). The UI is responsible for dealing with missing screenshots
   // appropriately (e.g. display a placeholder image instead).
   scoped_refptr<base::RefCountedBytes> screenshot_;
 
   // This member is not persisted with session restore.
   std::string extra_headers_;
 
-  // This member is cleared in |ResetForCommit| and not persisted.
-  scoped_refptr<SiteInstanceImpl> source_site_instance_;
-
   // Used for specifying base URL for pages loaded via data URLs. Only used and
   // persisted by Android WebView.
   GURL base_url_for_data_url_;
 
 #if defined(OS_ANDROID)
   // Used for passing really big data URLs from browser to renderers. Only used
   // and persisted by Android WebView.
   scoped_refptr<const base::RefCountedString> data_url_as_string_;
 #endif
 
@@ skipping 65 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_