Break cyclic dependency between CertDatabase and NSSCertDatabase.

net/cert/nss_cert_database.h

Index: net/cert/nss_cert_database.h
diff --git a/net/cert/nss_cert_database.h b/net/cert/nss_cert_database.h
index 1c4daf817937c83d328441d491b196be8858af86..120e50da9bec7b214c731c8e53d101ce165f8210 100644
--- a/net/cert/nss_cert_database.h
+++ b/net/cert/nss_cert_database.h
@@ -31,6 +31,8 @@ class CryptoModule;
 typedef std::vector<scoped_refptr<CryptoModule> > CryptoModuleList;
 
 // Provides functions to manipulate the NSS certificate stores.
+// Forwards notifications about certificate changes to the global CertDatabase
+// singleton.
 class NET_EXPORT NSSCertDatabase {
  public:
 
@@ -225,19 +227,6 @@ class NET_EXPORT NSSCertDatabase {
   // Check whether cert is stored in a hardware slot.
   bool IsHardwareBacked(const X509Certificate* cert) const;
 
-  // Registers |observer| to receive notifications of certificate changes.  The
-  // thread on which this is called is the thread on which |observer| will be
-  // called back with notifications.
-  // NOTE: CertDatabase::AddObserver should be preferred. Observers registered
-  // here will only receive notifications generated directly through the
-  // NSSCertDatabase, but not those from the CertDatabase. The CertDatabase
-  // observers will receive both.
-  void AddObserver(Observer* observer);
-
-  // Unregisters |observer| from receiving notifications.  This must be called
-  // on the same thread on which AddObserver() was called.
-  void RemoveObserver(Observer* observer);
-
   // Overrides task runner that's used for running slow tasks.
   void SetSlowTaskRunnerForTest(
       const scoped_refptr<base::TaskRunner>& task_runner);
@@ -261,6 +250,18 @@ class NET_EXPORT NSSCertDatabase {
  private:
   friend struct base::DefaultLazyInstanceTraits<NSSCertDatabase>;
 
+  // Registers |observer| to receive notifications of certificate changes.  The
+  // thread on which this is called is the thread on which |observer| will be
+  // called back with notifications.
+  // NOTE: Observers registered here will only receive notifications generated
+  // directly through the NSSCertDatabase, but not those from the CertDatabase.
+  // CertDatabase observers will receive all certificate notifications.
+  void AddObserver(Observer* observer);
+
+  // Unregisters |observer| from receiving notifications.  This must be called
+  // on the same thread on which AddObserver() was called.
+  void RemoveObserver(Observer* observer);
+
   // Notifies observers of the removal of |cert| and calls |callback| with
   // |success| as argument.
   void NotifyCertRemovalAndCallBack(scoped_refptr<X509Certificate> cert,
@@ -276,6 +277,9 @@ class NET_EXPORT NSSCertDatabase {
   // it may safely be used on the worker thread.
   static bool DeleteCertAndKeyImpl(scoped_refptr<X509Certificate> cert);
 
+  // A helper observer that forwards events from this database to CertDatabase.
+  scoped_ptr<Observer> cert_notification_forwarder_;
+
   // Task runner that should be used in tests if set.
   scoped_refptr<base::TaskRunner> slow_task_runner_for_test_;