Change the canonical way to include the C macros.h to <mojo/macros.h>.

mojo/public/c/system/tests/macros_unittest.cc

 // 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.
 
 // This file tests the C Mojo system macros and consists of "positive" tests,
 // i.e., those verifying that things work (without compile errors, or even
 // warnings if warnings are treated as errors).
 // TODO(vtl): Fix no-compile tests (which are all disabled; crbug.com/105388)
 // and write some "negative" tests.
 
-#include "mojo/public/c/system/macros.h"
+#include <mojo/macros.h>
 
 #include <assert.h>
 #include <stdint.h>
 #include <stdlib.h>
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace {
 
@@ skipping 53 matching lines @@
 #endif
 
 TEST(MacrosTest, Alignas) {
   EXPECT_EQ(1u, MOJO_ALIGNOF(StructAlignas1));
   EXPECT_EQ(4u, MOJO_ALIGNOF(StructAlignas4));
   EXPECT_EQ(8u, MOJO_ALIGNOF(StructAlignas8));
 }
 
 }  // namespace
 }  // namespace mojo