Make SkOSWindow return the sample count and stencil bit count for its GL context.

src/views/mac/SkOSWindow_Mac.mm

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #if defined(SK_BUILD_FOR_MAC)
 
 #import  <Cocoa/Cocoa.h>
@@ skipping 47 matching lines @@
 }
 
 void SkOSWindow::onAddMenu(const SkOSMenu* menu) {
     [(SkNSView*)fHWND onAddMenu:menu];
 }
 
 void SkOSWindow::onUpdateMenu(const SkOSMenu* menu) {
     [(SkNSView*)fHWND onUpdateMenu:menu];
 }
 
-bool SkOSWindow::attach(SkBackEndTypes attachType, int sampleCount) {
-    return [(SkNSView*)fHWND attach:attachType withMSAASampleCount:sampleCount];
+bool SkOSWindow::attach(SkBackEndTypes attachType, int sampleCount, AttachmentInfo* info) {
+    return [(SkNSView*)fHWND attach:attachType withMSAASampleCount:sampleCount andGetInfo:info];
 }
 
 void SkOSWindow::detach() {
     [(SkNSView*)fHWND detach];
 }
 
 void SkOSWindow::present() {
     [(SkNSView*)fHWND present];
 }
 
 #endif