Logging for registerHandler amidst applyChange #62

This commit adds logging for if there happens a modification to
DPIZoomChangeRegistry::dpiZoomChangeHandlers during the
DPIZoomChangeRegistry::applyChange operation while looping through
handlers for DPIZoomChangeHandler::handleDPIChange calls. The reason of
modification can be that some classes are loaded later and they call to
register their DPIZoomChangeHandler in the DPIZoomChangeRegistry::dpiZoomChangeHandlers.

contributes to #62 and #127

Author: amartya4256

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/internal/DPIZoomChangeRegistry.java

@@ -49,13 +49,17 @@ public static void applyChange(Widget widget, int newZoom, float scalingFactor)
 		if (widget == null) {
 			return;
 		}
+		int initialHandlerCount = dpiZoomChangeHandlers.entrySet().size();
 		for (Entry<Class<? extends Widget>, DPIZoomChangeHandler> entry : dpiZoomChangeHandlers.entrySet()) {
 			Class<? extends Widget> clazz = entry.getKey();
 			DPIZoomChangeHandler handler = entry.getValue();
 			if (clazz.isInstance(widget)) {
 				handler.handleDPIChange(widget, newZoom, scalingFactor);
 			}
 		}
+		if(initialHandlerCount != dpiZoomChangeHandlers.entrySet().size()) {
+			System.out.println("dpiZoomChangeHandler registration occured amidst processing a DPI Change event");
+		}
 		Event event = new Event();
 		event.type = SWT.ZoomChanged;
 		event.widget = widget;