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

chrome/browser/in_process_webkit/webkit_context.h

Index: chrome/browser/in_process_webkit/webkit_context.h
===================================================================
--- chrome/browser/in_process_webkit/webkit_context.h	(revision 36257)
+++ chrome/browser/in_process_webkit/webkit_context.h	(working copy)
@@ -14,7 +14,9 @@
 class WebKitThread;
 
 // There's one WebKitContext per profile.  Various DispatcherHost classes
-// have a pointer to the Context to store shared state.
+// have a pointer to the Context to store shared state.  Unfortunately, this
+// class has become a bit of a dumping ground for calls made on the UI thread
+// that need to be proxied over to the WebKit thread.
 //
 // This class is created on the UI thread and accessed on the UI, IO, and WebKit
 // threads.
@@ -43,6 +45,10 @@
   // last modified on or after the following time.
   void DeleteDataModifiedSince(const base::Time& cutoff);
 
+  // Delete the session storage namespace associated with this id.  Called from
+  // the UI thread.
+  void DeleteSessionStorageNamespace(int64 session_storage_namespace_id);
+
  private:
   friend class base::RefCountedThreadSafe<WebKitContext>;
   ~WebKitContext();