Fix for 'Simple Adblock' extension crashes

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 c883e1e6fc01da2971532015288057c544c30671..08ea0b9985df75e9388b91963f6ac7accea1ff82 100644
--- a/content/public/browser/navigation_controller.h
+++ b/content/public/browser/navigation_controller.h
@@ -13,6 +13,7 @@
 #include "base/strings/string16.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/global_request_id.h"
+#include "content/public/browser/session_storage_namespace.h"
 #include "content/public/common/page_transition_types.h"
 #include "content/public/common/referrer.h"
 #include "url/gurl.h"
@@ -27,14 +28,8 @@ namespace content {
 
 class BrowserContext;
 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.
 //
@@ -356,7 +351,7 @@ class NavigationController {
   // which cannot be used on iOS.
 #if !defined(OS_IOS)
   // Returns all the SessionStorageNamespace objects that this
-  // NavigationController knows about.
+  // NavigationController knows about, the map key is a StoragePartition id.
   virtual const SessionStorageNamespaceMap&
       GetSessionStorageNamespaceMap() const = 0;