QmlProfiler: Provide a vertical scroll bar for the timeline view.

The timeline can be vertically navigated by flicking, which is not very
appropriate for desktop applications. This change provides a scroll bar
and mouse wheel scrolling in addition to that. Also it makes the
vertical movement stop at the boundaries. The mouse wheel would exhibit
unintuitive behavior without it.

Change-Id: I5ef126525e452f46aa0a483a544345b8f618d829
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/plugins/qmlprofiler/qml/MainView.qml

@@ -307,6 +307,11 @@ Rectangle {
         height: root.height
         clip: true
         contentHeight: labels.height
+        boundsBehavior: Flickable.StopAtBounds
+
+        // ScrollView will try to deinteractivate it. We don't want that
+        // as the horizontal flickable is interactive, too.
+        onInteractiveChanged: interactive = true
 
         // ***** child items
         TimeMarks {
@@ -501,6 +506,11 @@ Rectangle {
         }
     }
 
+    ScrollView {
+        contentItem: vertflick
+        anchors.fill: parent
+    }
+
     SelectionRangeDetails {
         id: selectionRangeDetails
         visible: root.selectionRangeMode