Add a "session only" policy to the content settings.

chrome/browser/content_exceptions_table_model.cc

Index: chrome/browser/content_exceptions_table_model.cc
diff --git a/chrome/browser/content_exceptions_table_model.cc b/chrome/browser/content_exceptions_table_model.cc
index 93efed591b5c5780c5bfaba23a49f8db4539a9ed..a7cd9a48efd9618727b46516de5d3ec41e31c8b0 100644
--- a/chrome/browser/content_exceptions_table_model.cc
+++ b/chrome/browser/content_exceptions_table_model.cc
@@ -76,6 +76,8 @@ std::wstring ContentExceptionsTableModel::GetText(int row, int column_id) {
           return l10n_util::GetString(IDS_EXCEPTIONS_BLOCK_BUTTON);
         case CONTENT_SETTING_ASK:
           return l10n_util::GetString(IDS_EXCEPTIONS_ASK_BUTTON);
+        case CONTENT_SETTING_SESSION_ONLY:
+          return l10n_util::GetString(IDS_EXCEPTIONS_SESSION_ONLY_BUTTON);
         default:
           NOTREACHED();
       }