Bug 36981 call hierarchy: Search scope should be persisted
Search scope should be persisted when the platform shuts down or when the view is closed and reopened.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/callhierarchy/CallHierarchyViewPart.java
* called from ToggleOrientationAction.
     * @param orientation VIEW_ORIENTATION_HORIZONTAL or VIEW_ORIENTATION_VERTICAL
     */
    void setOrientation(int orientation) {
        if (fCurrentOrientation != orientation) {
            if ((fLocationViewer != null) && !fLocationViewer.getControl().isDisposed() &&
                        (fHierarchyLocationSplitter != null) &&
                        !fHierarchyLocationSplitter.isDisposed()) {
                if (orientation == VIEW_ORIENTATION_SINGLE) {
                    setShowCallDetails(false);
                } else {
                    if (fCurrentOrientation == VIEW_ORIENTATION_SINGLE) {
                        setShowCallDetails(true);
                    }
                    boolean horizontal = orientation == VIEW_ORIENTATION_HORIZONTAL;
                    fHierarchyLocationSplitter.setOrientation(horizontal ? SWT.HORIZONTAL
                                                                         : SWT.VERTICAL);
                }
                fHierarchyLocationSplitter.layout();
            }
            for (int i = 0; i < fToggleOrientationActions.length; i++) {
                fToggleOrientationActions[i].setChecked(orientation == fToggleOrientationActions[i].getOrientation());
            }
            fCurrentOrientation = orientation;
            fDialogSettings.put(DIALOGSTORE_VIEWORIENTATION, orientation);
        }
    }
    /**
     * called from ToggleCallModeAction.
     * @param orientation CALL_MODE_CALLERS or CALL_MODE_CALLEES