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

experimental/iOSSampleApp/SkSampleUIView.mm

 #import "SkSampleUIView.h"
 
 //#define SKWIND_CONFIG       SkBitmap::kRGB_565_Config
 #define SKWIND_CONFIG       SkBitmap::kARGB_8888_Config
 #define SKGL_CONFIG         kEAGLColorFormatRGB565
 //#define SKGL_CONFIG         kEAGLColorFormatRGBA8
 
 #define FORCE_REDRAW
 
 #include "SkCanvas.h"
@@ skipping 43 matching lines @@
                 break;
             // these guys use the native backend
             case SampleWindow::kGPU_DeviceType:
             case SampleWindow::kNullGPU_DeviceType:
                 fBackend = SkOSWindow::kNativeGL_BackEndType;
                 break;
             default:
                 SkASSERT(false);
                 break;
         }
-        
-        bool result = win->attach(fBackend, msaaSampleCount);
+        SkOSWindow::AttachmentInfo info;
+        bool result = win->attach(fBackend, msaaSampleCount, &info);
         if (!result) {
             SkDebugf("Failed to initialize GL");
             return;
         }
         fMSAASampleCount = msaaSampleCount;
         
         SkASSERT(NULL == fCurIntf);
         switch (win->getDeviceType()) {
             // these two don't use GL
             case SampleWindow::kRaster_DeviceType:
@@ skipping 82 matching lines @@
         if (NULL != fCurContext) {
             fCurContext->flush();
         }
 #endif
         win->present();
     }
     
     virtual void windowSizeChanged(SampleWindow* win) SK_OVERRIDE {
 #if SK_SUPPORT_GPU
         if (NULL != fCurContext) {
-            win->attach(fBackend, fMSAASampleCount);
+            SkOSWindow::AttachmentInfo info;
+
+            win->attach(fBackend, fMSAASampleCount, &info);
             
             glBindFramebuffer(GL_FRAMEBUFFER, fLayerFBO);
             GrBackendRenderTargetDesc desc;
             desc.fWidth = SkScalarRound(win->width());
             desc.fHeight = SkScalarRound(win->height());
             desc.fConfig = kSkia8888_GrPixelConfig;
             desc.fRenderTargetHandle = fLayerFBO;
-            glGetIntegerv(GL_SAMPLES, &desc.fSampleCnt);
-            glGetIntegerv(GL_STENCIL_BITS, &desc.fStencilBits);
-            
+            desc.fSampleCnt = info.fSampleCount;
+            desc.fStencilBits = info.fStencilBits;
+
             SkSafeUnref(fCurRenderTarget);
             fCurRenderTarget = fCurContext->wrapBackendRenderTarget(desc);
         }
 #endif
     }
     
     virtual GrContext* getGrContext() SK_OVERRIDE {
 #if SK_SUPPORT_GPU
         return fCurContext;
 #else
@@ skipping 284 matching lines @@
         if (gl) {
             [self performSelector:@selector(drawInGL) withObject:nil afterDelay:0];
         }
         else {
             [self performSelector:@selector(drawInRaster) withObject:nil afterDelay:0];
             [self setNeedsDisplay];
         }
     }
 }
 
+- (void)getAttachmentInfo:(SkOSWindow::AttachmentInfo*)info {
+    glBindRenderbuffer(GL_RENDERBUFFER, fGL.fRenderbuffer);
+    glGetRenderbufferParameteriv(GL_RENDERBUFFER,
+                                 GL_RENDERBUFFER_STENCIL_SIZE,
+                                 &info->fStencilBits);
+    glGetRenderbufferParameteriv(GL_RENDERBUFFER,
+                                 GL_RENDERBUFFER_SAMPLES_APPLE,
+                                 &info->fSampleCount);
+}
+
 @end