mojo::Serialize*_() calls now propogate/return validation errors.

mojo/public/cpp/bindings/lib/validation_errors.h

Index: mojo/public/cpp/bindings/lib/validation_errors.h
diff --git a/mojo/public/cpp/bindings/lib/validation_errors.h b/mojo/public/cpp/bindings/lib/validation_errors.h
index 43059c2e22b8ee6c18a089b1381bbdf4df66edb2..953ab5ee380f30c9ddff6f09ac517bfd0288e296 100644
--- a/mojo/public/cpp/bindings/lib/validation_errors.h
+++ b/mojo/public/cpp/bindings/lib/validation_errors.h
@@ -78,45 +78,13 @@ class ValidationErrorObserverForTesting {
   MOJO_DISALLOW_COPY_AND_ASSIGN(ValidationErrorObserverForTesting);
 };
 
-// Used only by MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING. Don't use it directly.
-//
-// The function returns true if the error is recorded (by a
-// SerializationWarningObserverForTesting object), false otherwise.
-bool ReportSerializationWarning(ValidationError error);
-
-// Only used by serialization tests and when there is only one thread doing
-// message serialization.
-class SerializationWarningObserverForTesting {
- public:
-  SerializationWarningObserverForTesting();
-  ~SerializationWarningObserverForTesting();
-
-  ValidationError last_warning() const { return last_warning_; }
-  void set_last_warning(ValidationError error) { last_warning_ = error; }
-
- private:
-  ValidationError last_warning_;
-
-  MOJO_DISALLOW_COPY_AND_ASSIGN(SerializationWarningObserverForTesting);
-};
-
 }  // namespace internal
 }  // namespace mojo
 
-// In debug build, logs a serialization warning if |condition| evaluates to
-// true:
-//   - if there is a SerializationWarningObserverForTesting object alive,
-//     records |error| in it;
-//   - otherwise, logs a fatal-level message.
-// |error| is the validation error that will be triggered by the receiver
-// of the serialzation result.
-//
-// In non-debug build, does nothing (not even compiling |condition|).
-#define MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(                        \
-    condition, error, description)                                       \
-  MOJO_DLOG_IF(FATAL, (condition) && !ReportSerializationWarning(error)) \
-      << "The outgoing message will trigger "                            \
-      << ValidationErrorToString(error) << " at the receiving side ("    \
-      << description << ").";
+// In a debug build, logs a serialization warning.
+#define MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(error, description) \
+  MOJO_DLOG(WARNING) << "The outgoing message will trigger "         \
+                     << ValidationErrorToString(error)               \
+                     << " at the receiving side (" << description << ")."
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_VALIDATION_ERRORS_H_