Update to allow packed depth-stencil on ES3

R=robertphillips@google.com

Author: bsalomon@google.com

Review URL: https://chromiumcodereview.appspot.com/22880023

git-svn-id: http://skia.googlecode.com/svn/trunk@11130 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index 1488e75..8ca88c1 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -501,7 +501,8 @@
 
         fStencilFormats.push_back() = gS8;
         //fStencilFormats.push_back() = gS16;
-        if (ctxInfo.hasExtension("GL_OES_packed_depth_stencil")) {
+        if (ctxInfo.version() >= GR_GL_VER(3,0) ||
+            ctxInfo.hasExtension("GL_OES_packed_depth_stencil")) {
             fStencilFormats.push_back() = gD24S8;
         }
         if (ctxInfo.hasExtension("GL_OES_stencil4")) {