centralize message box handling in adapters

src/plugins/debugger/gdb/abstractgdbadapter.h

@@ -99,6 +99,8 @@ protected:
         { m_engine->debugMessage(msg); }
     void showStatusMessage(const QString &msg) const
         { m_engine->showStatusMessage(msg); }
+    void showMessageBox(int icon, const QString &title, const QString &text) const
+        { m_engine->showMessageBox(icon, title, text); }
 
     GdbEngine * const m_engine;
 };

src/plugins/debugger/gdb/remotegdbadapter.cpp

@@ -119,7 +119,7 @@ void RemoteGdbAdapter::uploadProcError(QProcess::ProcessError error)
     }
 
     m_engine->showStatusMessage(msg);
-    QMessageBox::critical(m_engine->mainWindow(), tr("Error"), msg);
+    showMessageBox(QMessageBox::Critical, tr("Error"), msg);
 }
 
 void RemoteGdbAdapter::readUploadStandardOutput()

src/plugins/debugger/gdb/termgdbadapter.cpp

@@ -147,7 +147,7 @@ void TermGdbAdapter::shutdown()
 
 void TermGdbAdapter::stubError(const QString &msg)
 {
-    QMessageBox::critical(m_engine->mainWindow(), tr("Debugger Error"), msg);
+    showMessageBox(QMessageBox::Critical, tr("Debugger Error"), msg);
 }
 
 void TermGdbAdapter::stubExited()