Introduce all the plumbing for Session Storage. This mostly consists of crea...

chrome/browser/tab_contents/navigation_controller.h

Index: chrome/browser/tab_contents/navigation_controller.h
===================================================================
--- chrome/browser/tab_contents/navigation_controller.h	(revision 36257)
+++ chrome/browser/tab_contents/navigation_controller.h	(working copy)
@@ -374,6 +374,11 @@
   // if it was restored from a previous session.  (-1 otherwise)
   int max_restored_page_id() const { return max_restored_page_id_; }
 
+  // The session storage namespace id that all child render views should use.
+  int64 session_storage_namespace_id() const {
+    return session_storage_namespace_id_;
+  }
+
   // Disables checking for a repost and prompting the user. This is used during
   // testing.
   static void DisablePromptOnRepost();
@@ -528,6 +533,9 @@
   // Whether a user gesture has been observed since the last navigation.
   bool user_gesture_observed_;
 
+  // The session storage id that any (indirectly) owned RenderView should use.
+  int64 session_storage_namespace_id_;
+
   // Should Reload check for post data? The default is true, but is set to false
   // when testing.
   static bool check_for_repost_;