QmlProfiler: flush on new trace

Discard pending data if a new trace arrives while an old one
was still being processed.  If we don't, the data of both
traces gets mixed, leading to a possible crash.

Change-Id: Ibba7df06f6a4b7e93d00f6fa1fa4802baf3a1731
Reviewed-by: Kai Koehne <kai.koehne@nokia.com>

src/plugins/qmlprofiler/qmlprofilerclientmanager.cpp

@@ -123,6 +123,13 @@ void QmlProfilerClientManager::clearBufferedData()
         d->v8clientplugin.data()->clearData();
 }
 
+void QmlProfilerClientManager::discardPendingData()
+{
+    if (d->connection)
+        d->connection->flush();
+    clearBufferedData();
+}
+
 ////////////////////////////////////////////////////////////////
 // Internal
 void QmlProfilerClientManager::connectClient(quint16 port)

src/plugins/qmlprofiler/qmlprofilerclientmanager.h

@@ -55,6 +55,7 @@ public:
     void setOstConnection(QString ostDevice);
 
     void clearBufferedData();
+    void discardPendingData();
 
 signals:
     void connectionFailed();

src/plugins/qmlprofiler/qmlprofilertool.cpp

@@ -476,6 +476,7 @@ void QmlProfilerTool::updateTimeDisplay()
 void QmlProfilerTool::clearData()
 {
     d->m_profilerDataModel->clear();
+    d->m_profilerConnections->discardPendingData();
 }
 
 void QmlProfilerTool::clearDisplay()