Fix a memory leak in PasswordStoreMac

chrome/browser/password_manager/password_store_mac_internal.h

Index: chrome/browser/password_manager/password_store_mac_internal.h
diff --git a/chrome/browser/password_manager/password_store_mac_internal.h b/chrome/browser/password_manager/password_store_mac_internal.h
index 21fe031c1f5dc6382c2cf17bb0107ad0a184810e..4a6cdbff63400c4ec2cf2edd7e81058e92b4c89c 100644
--- a/chrome/browser/password_manager/password_store_mac_internal.h
+++ b/chrome/browser/password_manager/password_store_mac_internal.h
@@ -10,6 +10,7 @@
 #include <string>
 #include <vector>
 
+#include "base/memory/scoped_ptr.h"
 #include "components/autofill/core/common/password_form.h"
 #include "crypto/apple_keychain.h"
 
@@ -33,8 +34,7 @@ class MacKeychainPasswordFormAdapter {
   // Returns the PasswordForm for the Keychain entry that matches |form| on all
   // of the fields that uniquely identify a Keychain item, or NULL if there is
   // no such entry.
-  // Caller is responsible for deleting the returned form.
-  autofill::PasswordForm* PasswordExactlyMatchingForm(
+  scoped_ptr<autofill::PasswordForm> PasswordExactlyMatchingForm(
       const autofill::PasswordForm& query_form);
 
   // Returns true if the keychain contains any items that are mergeable with