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

experimental/iOSSampleApp/Shared/SkUIView.mm

 #import "SkUIView.h"
 #include "SkCanvas.h"
 #include "SkCGUtils.h"
 @implementation SkUIView
 
 @synthesize fWind, fTitleItem, fOptionsDelegate;
 
 - (id)initWithDefaults {
     fWind = NULL;
     return self;
@@ skipping 75 matching lines @@
 - (void)setSkTitle:(const char *)title {
     if (fTitleItem) {
         fTitleItem.title = [NSString stringWithUTF8String:title];
     }
 }
 
 - (BOOL)onHandleEvent:(const SkEvent&)evt {
     return false;
 }
 
+- (void)getAttachmentInfo:(SkOSWindow::AttachmentInfo*)info {
+    // we don't have a GL context.
+    info->fSampleCount = 0;
+    info->fStencilBits = 0;
+}
+
+
 #include "SkOSMenu.h"
 - (void)onAddMenu:(const SkOSMenu*)menu {
     [self.fOptionsDelegate view:self didAddMenu:menu];
 }
 - (void)onUpdateMenu:(SkOSMenu*)menu {
     [self.fOptionsDelegate view:self didUpdateMenu:menu];
 }
 
 - (void)postInvalWithRect:(const SkIRect*)r {
     [self performSelector:@selector(drawInRaster) withObject:nil afterDelay:0];
     [self setNeedsDisplay];
 }
 
 @end