Fix SessionStorage confusion between RenderViewHostImpl and NavigationController.

content/public/browser/navigation_controller.h

Index: content/public/browser/navigation_controller.h
diff --git a/content/public/browser/navigation_controller.h b/content/public/browser/navigation_controller.h
index 9770223038ae30ee455b8100c6a9c644d287be44..3b93ef145a864001b4d5bf61b93f56e99b330f98 100644
--- a/content/public/browser/navigation_controller.h
+++ b/content/public/browser/navigation_controller.h
@@ -30,11 +30,6 @@ class NavigationEntry;
 class SessionStorageNamespace;
 class WebContents;
 
-// Used to store the mapping of a StoragePartition id to
-// SessionStorageNamespace.
-typedef std::map<std::string, scoped_refptr<SessionStorageNamespace> >
-    SessionStorageNamespaceMap;
-
 // A NavigationController maintains the back-forward list for a WebContents and
 // manages all navigation within that list.
 //
@@ -345,14 +340,7 @@ class NavigationController {
   // Session storage depends on dom_storage that depends on WebKit::WebString,
   // which cannot be used on iOS.
 #if !defined(OS_IOS)
-  // Returns all the SessionStorageNamespace objects that this
-  // NavigationController knows about.
-  virtual const SessionStorageNamespaceMap&
-      GetSessionStorageNamespaceMap() const = 0;
-
-  // TODO(ajwong): Remove this once prerendering, instant, and session restore
-  // are migrated.
-  virtual SessionStorageNamespace* GetDefaultSessionStorageNamespace() = 0;
+  virtual SessionStorageNamespace* GetSessionStorageNamespace() = 0;
 #endif
 
   // Sets the max restored page ID this NavigationController has seen, if it