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..baffc514a78e2adee3de179d0507b354fbb08eb8 100644
--- a/mojo/public/cpp/bindings/lib/validation_errors.h
+++ b/mojo/public/cpp/bindings/lib/validation_errors.h
@@ -103,8 +103,7 @@ class SerializationWarningObserverForTesting {
 }  // namespace internal
 }  // namespace mojo
 
-// In debug build, logs a serialization warning if |condition| evaluates to
-// true:
+// In debug build, logs a serialization warning:
 //   - if there is a SerializationWarningObserverForTesting object alive,
 //     records |error| in it;
 //   - otherwise, logs a fatal-level message.
@@ -112,11 +111,10 @@ class SerializationWarningObserverForTesting {
 // 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 << ").";
+#define MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(error, description)  \
+  MOJO_DLOG_IF(FATAL, !ReportSerializationWarning(error))             \
+      << "The outgoing message will trigger "                         \
+      << ValidationErrorToString(error) << " at the receiving side (" \
+      << description << ")."
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_VALIDATION_ERRORS_H_