Introduce content::PageState (again).

content/public/browser/navigation_entry.h

Index: content/public/browser/navigation_entry.h
diff --git a/content/public/browser/navigation_entry.h b/content/public/browser/navigation_entry.h
index e675d2f01aa2ee83566c673a83db496ecad323f5..05f4d7366fe22bad2481000e942bc0ba6f8e37bc 100644
--- a/content/public/browser/navigation_entry.h
+++ b/content/public/browser/navigation_entry.h
@@ -19,6 +19,7 @@ class GURL;
 
 namespace content {
 
+class PageState;
 struct FaviconStatus;
 struct SSLStatus;
 
@@ -75,6 +76,7 @@ class NavigationEntry {
   virtual void SetTitle(const string16& title) = 0;
   virtual const string16& GetTitle() const = 0;
 
+  // XXX

[joth, 2013/11/26 00:46:09]

Just to check, was this XXX indicating something important? (I propose  to
remove it in https://codereview.chromium.org/84703003 else...)

[darin (slow to review), 2013/11/26 05:36:42]

Whoops, that was not supposed to be committed. It was a reminder to me to revise
this comment block. Where it says "content state", it should instead say "page
state." I'll write a patch for that.

   // Content state is an opaque blob created by WebKit that represents the
   // state of the page. This includes form entries and scroll position for each
   // frame. We store it so that we can supply it back to WebKit to restore form
@@ -83,8 +85,8 @@ class NavigationEntry {
   // WARNING: This state is saved to the file and used to restore previous
   // states. If the format is modified in the future, we should still be able to
   // deal with older versions.
-  virtual void SetContentState(const std::string& state) = 0;
-  virtual const std::string& GetContentState() const = 0;
+  virtual void SetPageState(const PageState& state) = 0;
+  virtual const PageState& GetPageState() const = 0;
 
   // Describes the current page that the tab represents. This is the ID that the
   // renderer generated for the page and is how we can tell new versus