DiffEditorController: Add an option to set a syntax highlighter

Change-Id: I66fc252e7ccc168fd32ed7100cc9af7f940dc3e0
Reviewed-by: André Hartmann <aha_1980@gmx.de>

src/plugins/diffeditor/diffeditordocument.cpp

@@ -179,6 +179,13 @@ void DiffEditorDocument::setDescription(const QString &description)
     emit descriptionChanged();
 }
 
+void DiffEditorDocument::setDescriptionSyntaxHighlighterCreator(
+    const std::function<TextEditor::SyntaxHighlighter *()> &creator)
+{
+    m_descriptionHighlighter = creator;
+    emit descriptionHighlighterChanged();
+}
+
 QString DiffEditorDocument::description() const
 {
     return m_description;