Mojo: Suppress validation error logging in some tests

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_VALIDATION_ERRORS_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_VALIDATION_ERRORS_H_
 
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/macros.h"
@@ skipping 71 matching lines @@
 MOJO_CPP_BINDINGS_EXPORT void ReportValidationError(
     ValidationContext* context,
     ValidationError error,
     const char* description = nullptr);
 
 MOJO_CPP_BINDINGS_EXPORT void ReportValidationErrorForMessage(
     mojo::Message* message,
     ValidationError error,
     const char* description = nullptr);
 
+// This class may be used by tests to suppress validation error logging. This is
+// not thread-safe and must only be instantiated on the main thread with no
+// other threads using Mojo bindings at the time of construction or destruction.
+class MOJO_CPP_BINDINGS_EXPORT ScopedSuppressValidationErrorLoggingForTests {
+ public:
+  ScopedSuppressValidationErrorLoggingForTests();
+  ~ScopedSuppressValidationErrorLoggingForTests();
+
+ private:
+  const bool was_suppressed_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedSuppressValidationErrorLoggingForTests);
+};
+
 // Only used by validation tests and when there is only one thread doing message
 // validation.
 class MOJO_CPP_BINDINGS_EXPORT ValidationErrorObserverForTesting {
  public:
   explicit ValidationErrorObserverForTesting(const base::Closure& callback);
   ~ValidationErrorObserverForTesting();
 
   ValidationError last_error() const { return last_error_; }
   void set_last_error(ValidationError error) {
     last_error_ = error;
@@ skipping 42 matching lines @@
 //
 // In non-debug build, does nothing (not even compiling |condition|).
 #define MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(condition, error,    \
                                                  description)         \
   DLOG_IF(FATAL, (condition) && !ReportSerializationWarning(error))   \
       << "The outgoing message will trigger "                         \
       << ValidationErrorToString(error) << " at the receiving side (" \
       << description << ").";
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_VALIDATION_ERRORS_H_