Temporarily disable all calls of CGS private APIs.

ui/views/cocoa/bridged_native_widget.mm

Index: ui/views/cocoa/bridged_native_widget.mm
diff --git a/ui/views/cocoa/bridged_native_widget.mm b/ui/views/cocoa/bridged_native_widget.mm
index 6f5dec0f96864ede56c8a7cf940de5ebf964aa92..0b739ce127d24a084d65397d96595a3b46711098 100644
--- a/ui/views/cocoa/bridged_native_widget.mm
+++ b/ui/views/cocoa/bridged_native_widget.mm
@@ -1145,8 +1145,11 @@ void BridgedNativeWidget::AddCompositorSuperview() {
     // solid background, but make the CALayer transparent.
     if (base::mac::IsOSYosemiteOrLater()) {
       [background_layer setOpacity:kYosemiteMenuOpacity];
-      CGSSetWindowBackgroundBlurRadius(
-          _CGSDefaultConnection(), [window_ windowNumber], kYosemiteMenuBlur);
+
+      // TODO(erikchen): Temporarily disabled. https://crbug.com/515627.
+      // CGSSetWindowBackgroundBlurRadius(
+      //     _CGSDefaultConnection(), [window_ windowNumber],
+      //     kYosemiteMenuBlur);
       // The blur effect does not occur with a fully transparent (or fully
       // layer-backed) window. Setting a window background will use square
       // corners, so ask the contentView to draw one instead.