Add keyboard zoom support (Cmd + +/-) for SWT Browser on macOS to match Windows Ctrl+MouseWheel behavior

[tobiasmelcher]

Zooming inside the SWT Browser control does not work on macOS (e.g., in an “element info popup” or similar contexts). Users expect consistent cross-platform behavior:

On Windows: Ctrl + MouseWheel zooms browser content in/out.
On macOS: No equivalent functionality exists (Cmd + MouseWheel or Cmd + +/- does not zoom).

This inconsistency causes a poor user experience for macOS users, where standard zoom shortcuts like Cmd + + (zoom in) and Cmd + - (zoom out) are expected to work.

Proposed Solution
Add a macOS-specific KeyListener to the Browser to intercept Cmd + + and Cmd + -, then apply a WebKit-compatible CSS transform via JavaScript to scale content if javascript support is enabled.

Could following code snippet be somehow integrated in the macOS specific implementation of the Browser control class?

if (Util.isMac()) {
			browser.addKeyListener(new KeyAdapter() {
				double zoomLevel = 1.0;
 
				public void keyPressed(org.eclipse.swt.events.KeyEvent e) {
					try {
						KeyStroke increaseSizeKeyStroke = org.eclipse.jface.bindings.keys.KeyStroke.getInstance("M1+="); //$NON-NLS-1$
						KeyStroke decreaseSizeKeyStroke = org.eclipse.jface.bindings.keys.KeyStroke.getInstance("M1+-"); //$NON-NLS-1$
						int accelerator = SWTKeySupport.convertEventToUnmodifiedAccelerator(e);
						KeyStroke stroke = SWTKeySupport.convertAcceleratorToKeyStroke(accelerator);
						if (decreaseSizeKeyStroke.equals(stroke)) {
							this.zoomLevel -= 0.1;
							zoom();
							e.doit = false;
						} else if (increaseSizeKeyStroke.equals(stroke)) {
							this.zoomLevel += 0.1;
							zoom();
							e.doit = false;
						}
					} catch (ParseException e1) {
						e1.printStackTrace();
					}
				}
 
				private void zoom() {
					browser.execute("document.body.style.webkitTransform = 'scale(" + this.zoomLevel + ")';" //$NON-NLS-1$ //$NON-NLS-2$
							+ "document.body.style.webkitTransformOrigin = '0 0';"); //$NON-NLS-1$
				}
			});
		}

[iloveeclipse]

@tobiasmelcher : FYI, M1+= doesn't work for many (non-US) keyboard layouts, see microsoft/copilot-eclipse-feedback#118.
If something like above would be added, it should also add M1++ shortcut support.

Also please note, on Linux we also don't have zoom in/out support in webkit, so if some kind of fix will be added to webkit, would be nice to have it on Linux too.