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/core/SkShader.h b/include/core/SkShader.h
index 5efd46d..91d431f 100644
--- a/include/core/SkShader.h
+++ b/include/core/SkShader.h
@@ -476,7 +476,7 @@
     SK_DEFINE_FLATTENABLE_TYPE(SkShader)
 
 protected:
-    void flatten(SkWriteBuffer&) const SK_OVERRIDE;
+    void flatten(SkWriteBuffer&) const override;
 
     bool computeTotalInverse(const ContextRec&, SkMatrix* totalInverse) const;