C++11 override should now be supported by all of {bots,Chrome,Android,Mozilla}

NOPRESUBMIT=true

BUG=skia:
DOCS_PREVIEW= https://skia.org/?cl=1037793002

Review URL: https://codereview.chromium.org/1037793002
diff --git a/include/gpu/gl/SkGLContext.h b/include/gpu/gl/SkGLContext.h
index 57456c2..6ca7bf5 100644
--- a/include/gpu/gl/SkGLContext.h
+++ b/include/gpu/gl/SkGLContext.h
@@ -19,7 +19,7 @@
 public:
     SK_DECLARE_INST_COUNT(SkGLContext)
 
-    ~SkGLContext() SK_OVERRIDE;
+    ~SkGLContext() override;
 
     bool isValid() const { return NULL != gl(); }