Add common interface for text formats inside syntax highlighter

Change-Id: I87f64446161a57aea0896f68e4eafacef791969b
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/plugins/git/annotationhighlighter.cpp

@@ -35,9 +35,8 @@ namespace Git {
 namespace Internal {
 
 GitAnnotationHighlighter::GitAnnotationHighlighter(const ChangeNumbers &changeNumbers,
-                                                   const QColor &bg,
                                                    QTextDocument *document) :
-    VcsBase::BaseAnnotationHighlighter(changeNumbers, bg, document),
+    VcsBase::BaseAnnotationHighlighter(changeNumbers, document),
     m_blank(QLatin1Char(' '))
 {
 }