OOPIF: Support session restore by combining/splitting frame states.

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 8d97ef39871055859583b4c36a48b7e4d78c0423..b009b70da4c136e17d8c1285dbc9e745ece5aa10 100644
--- a/content/browser/frame_host/navigation_entry_impl.h
+++ b/content/browser/frame_host/navigation_entry_impl.h
@@ -13,6 +13,7 @@
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/site_instance_impl.h"
 #include "content/common/frame_message_enums.h"
+#include "content/common/page_state_serialization.h"
 #include "content/public/browser/favicon_status.h"
 #include "content/public/browser/global_request_id.h"
 #include "content/public/browser/navigation_entry.h"
@@ -186,7 +187,7 @@ class CONTENT_EXPORT NavigationEntryImpl
                              SiteInstanceImpl* site_instance,
                              const GURL& url,
                              const Referrer& referrer,
-                             const PageState& page_state);
+                             const ExplodedFrameState& frame_state);
 
   // Returns the FrameNavigationEntry corresponding to |frame_tree_node|, if
   // there is one in this NavigationEntry.
@@ -201,6 +202,11 @@ class CONTENT_EXPORT NavigationEntryImpl
   FrameNavigationEntry* GetFrameEntryByUniqueName(
       const std::string& unique_name) const;
 
+  // In OOPIF modes, this updates the cached copy of the full PageState whenever
+  // a frame's individual state changes. Keeping a cached copy is necessary to
+  // be able to return a const ref from GetPageState.
+  void UpdatePageState();
+
   void set_unique_id(int unique_id) {
     unique_id_ = unique_id;
   }
@@ -394,6 +400,12 @@ class CONTENT_EXPORT NavigationEntryImpl
   base::Time timestamp_;
   int http_status_code_;
 
+  // In default Chrome, this is the PageState reported from the renderer. In
+  // OOPIF modes, this is a cached copy of the PageState generated from the
+  // various FrameNavigationEntry::frame_states. In either case, it is persisted
+  // to support session/tab restore.
+  PageState page_state_;
+
   // This member is not persisted with session restore because it is transient.
   // If the post request succeeds, this field is cleared since the same
   // information is stored in |content_state_| above. It is also only shallow