QmlProfiler: Use anchors to determine the size of the timebar background

For some reason, when the timeline width is 0, the background width can
get negative, if using bindings; it works fine when using anchors.

Change-Id: I5eb76f83b9c41c1a71a135082770079cedc7f16c
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/plugins/qmlprofiler/qml/MainView.qml

@@ -303,8 +303,7 @@ Rectangle {
     Flickable {
         id: vertflick
         flickableDirection: Flickable.VerticalFlick
-        width: parent.width
-        height: root.height
+        anchors.fill: parent
         clip: true
         contentHeight: labels.height
         boundsBehavior: Flickable.StopAtBounds
@@ -318,8 +317,8 @@ Rectangle {
             id: backgroundMarks
             y: vertflick.contentY
             height: vertflick.height
-            width: flick.width
-            anchors.left: flick.left
+            anchors.right: parent.right
+            anchors.left: labels.right
         }
 
         Flickable {