[win32] ImageDataProvider getBounds performance

This commit improves the performance of Image#getBounds if an
ImageDataProvider is used and no matching handle exists yet. This only
affects the windows implementation.

Author: akoch-yatta

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/Image.java

@@ -2330,8 +2330,14 @@ private ImageHandle initializeHandleFromSource(int zoom) {
 
 	@Override
 	protected Rectangle getBounds(int zoom) {
-		ImageData imageData = getImageData(zoom);
-		return new Rectangle(0, 0, imageData.width, imageData.height);
+		if (cachedImageData.containsKey(zoom)) {
+			ImageData imageData = cachedImageData.get(zoom);
+			return new Rectangle(0, 0, imageData.width, imageData.height);
+		}
+		ElementAtZoom<ImageData> imageDataAtZoom = loadImageData(zoom);
+		ImageData imageData = imageDataAtZoom.element();
+		Rectangle currentSize = new Rectangle(0, 0, imageData.width, imageData.height);
+		return Win32DPIUtils.scaleBounds(currentSize, zoom, imageDataAtZoom.zoom());
 	}
 }