Fix build break in assert

git-svn-id: http://skia.googlecode.com/svn/trunk@11771 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index dd45b25..7ded54d 100644
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -438,7 +438,7 @@
              !(inDesc.fFlags & kNoStencil_GrTextureFlagBit));
 
     // Renderable A8 targets are not universally supported (e.g., not on ANGLE)
-    SkASSERT(this->isConfigRenderable(kAlpha_8_GrPixelConfig) ||
+    SkASSERT(this->isConfigRenderable(kAlpha_8_GrPixelConfig, inDesc.fSampleCnt > 0) ||
              !(inDesc.fFlags & kRenderTarget_GrTextureFlagBit) ||
              (inDesc.fConfig != kAlpha_8_GrPixelConfig));