Enable proper zooming of checkbox and radio button on Win and Mac.

Source/core/rendering/RenderThemeChromiumMac.mm

Index: Source/core/rendering/RenderThemeChromiumMac.mm
diff --git a/Source/core/rendering/RenderThemeChromiumMac.mm b/Source/core/rendering/RenderThemeChromiumMac.mm
index 4f4c13e7f78ad73ff7df239370e25d8930f9e1ca..e7c15334b0ada54bcf6867e878bd7bb89abdd4fe 100644
--- a/Source/core/rendering/RenderThemeChromiumMac.mm
+++ b/Source/core/rendering/RenderThemeChromiumMac.mm
@@ -1962,4 +1962,12 @@ bool RenderThemeChromiumMac::paintMediaToggleClosedCaptionsButton(RenderObject*
     return RenderMediaControlsChromium::paintMediaControlsPart(MediaShowClosedCaptionsButton, object, paintInfo, rect);
 }
 
+bool RenderThemeChromiumMac::shouldUseFallbackTheme(RenderStyle* style) const
+{
+    ControlPart part = style->appearance();
+    if (part == CheckboxPart || part == RadioPart)
+        return style->effectiveZoom() != 1;
+    return false;
+}
+
 } // namespace WebCore