ObserverList::HasObserver now takes a const pointer.

chromeos/dbus/session_manager_client.cc

Index: chromeos/dbus/session_manager_client.cc
diff --git a/chromeos/dbus/session_manager_client.cc b/chromeos/dbus/session_manager_client.cc
index 5a67ee8a55519af6ae376ccd245df83776733a95..a3e0ced7de598f76a13edbe67d3a964bb86a409f 100644
--- a/chromeos/dbus/session_manager_client.cc
+++ b/chromeos/dbus/session_manager_client.cc
@@ -84,7 +84,7 @@ class SessionManagerClientImpl : public SessionManagerClient {
     observers_.RemoveObserver(observer);
   }
 
-  virtual bool HasObserver(Observer* observer) override {
+  virtual bool HasObserver(const Observer* observer) const override {
     return observers_.HasObserver(observer);
   }
 
@@ -583,7 +583,7 @@ class SessionManagerClientStubImpl : public SessionManagerClient {
   virtual void RemoveObserver(Observer* observer) override {
     observers_.RemoveObserver(observer);
   }
-  virtual bool HasObserver(Observer* observer) override {
+  virtual bool HasObserver(const Observer* observer) const override {
     return observers_.HasObserver(observer);
   }
   virtual void EmitLoginPromptVisible() override {}