Git: Factor out resolving of bin directory on Windows

Change-Id: Ifbafa0f5cb8329faedfd1da3674b87e46001acc3
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/git/gerrit/gerritplugin.h

@@ -30,6 +30,8 @@
 #ifndef GERRIT_INTERNAL_GERRITPLUGIN_H
 #define GERRIT_INTERNAL_GERRITPLUGIN_H
 
+#include <utils/fileutils.h>
+
 #include <QObject>
 #include <QPointer>
 #include <QSharedPointer>
@@ -62,6 +64,7 @@ public:
     bool initialize(Core::ActionContainer *ac);
 
     static QString gitBinary();
+    static Utils::FileName gitBinDirectory();
     static QString branch(const QString &repository);
     void addToLocator(Core::CommandLocator *locator);
     void push(const QString &topLevel);