first draft of error checking / reporting API

src/core/SkErrorInternals.h

+
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkErrorInternals_DEFINED
+#define SkErrorInternals_DEFINED
+
+#include "SkError.h"
+
+class SkErrorInternals {
+    
+public:
+    static void ClearError();
+    static void SetError(SkError code, const char *fmt, ...);
+    static SkError GetLastError();
+    static const char *GetLastErrorString();
+    static void SetErrorCallback(SkErrorCallbackFunction cb, void *context);
+    static void DefaultErrorCallback(SkError code, void *context);
+};
+ 
+
+
+#endif /* SkErrorInternals_DEFINED */