QmlProfiler: Add another data state "ClearingData"

This allows us to steer the timeline models in a more fine grained
way and avoid duplicate processing of the same data. We don't need
to rebuild everything on stateChanged of the model manager then.

Task-number: QTCREATORBUG-10950
Change-Id: I2aa9a96a33c602f062fc3b644ac06280ba7cd45a
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/plugins/qmlprofiler/qmlprofilermodelmanager.cpp

@@ -57,6 +57,9 @@ void QmlProfilerDataState::setState(QmlProfilerDataState::State state)
         return;
 
     switch (state) {
+        case ClearingData:
+            QTC_ASSERT(m_state == Done || m_state == Empty, /**/);
+        break;
         case Empty:
             // if it's not empty, complain but go on
             QTC_ASSERT(m_modelManager->isEmpty(), /**/);
@@ -345,6 +348,7 @@ QmlProfilerDataState::State QmlProfilerModelManager::state() const
 
 void QmlProfilerModelManager::clear()
 {
+    setState(QmlProfilerDataState::ClearingData);
     for (int i = 0; i < d->partialCounts.count(); i++)
         d->partialCounts[i] = 0;
     d->progress = 0;