QmlProfiler: Add EngineControl

With EngineControl multiple QQuickViews can be profiled in one
profiler if they're all running in the same thread. As the QML
engines are never run in parallel then this results in useful
data.

Change-Id: I83a34fb81fd466c5cac838b096c1b1f322ded882
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/plugins/qmlprofiler/qmlprofilermodelmanager.cpp

@@ -132,6 +132,18 @@ void QmlProfilerTraceTime::setEndTime(qint64 time)
     }
 }
 
+void QmlProfilerTraceTime::decreaseStartTime(qint64 time)
+{
+    if (m_startTime > time)
+        setStartTime(time);
+}
+
+void QmlProfilerTraceTime::increaseEndTime(qint64 time)
+{
+    if (m_endTime < time)
+        setEndTime(time);
+}
+
 
 } // namespace Internal