message: Add DAWN_NO_DISCARD to ErrorData
  ErrorData should not be discarded. The error must be handled.
diff: #ifndef DAWNNATIVE_ERRORDATA_H_
  #define DAWNNATIVE_ERRORDATA_H_
  +#include "common/Compiler.h"
  +
  #include <cstdint>
  #include <memory>
  #include <string>
  @@ -31,9 +33,9 @@ namespace dawn {
  namespace dawn_native {
  enum class InternalErrorType : uint32_t;
  - class ErrorData {
  + class DAWN_NO_DISCARD ErrorData {
  public:
  - static std::unique_ptr<ErrorData> Create(InternalErrorType type,
  + static DAWN_NO_DISCARD std::unique_ptr<ErrorData> Create(InternalErrorType type,
  std::string message,
  const char* file,
  const char* function,
  