Add compat to Crashpad

compat/mac/AvailabilityMacros.h

Index: compat/mac/AvailabilityMacros.h
diff --git a/compat/mac/AvailabilityMacros.h b/compat/mac/AvailabilityMacros.h
new file mode 100644
index 0000000000000000000000000000000000000000..69de4f69387b9f9c4e8d5bd38699010979b76f8b
--- /dev/null
+++ b/compat/mac/AvailabilityMacros.h
@@ -0,0 +1,50 @@
+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef CRASHPAD_COMPAT_MAC_AVAILABILITYMACROS_H_
+#define CRASHPAD_COMPAT_MAC_AVAILABILITYMACROS_H_
+
+#include_next <AvailabilityMacros.h>
+
+// 10.6 SDK
+
+#ifndef MAC_OS_X_VERSION_10_6
+#define MAC_OS_X_VERSION_10_6 1060
+#endif
+
+// 10.7 SDK
+
+#ifndef MAC_OS_X_VERSION_10_7
+#define MAC_OS_X_VERSION_10_7 1070
+#endif
+
+// 10.8 SDK
+
+#ifndef MAC_OS_X_VERSION_10_8
+#define MAC_OS_X_VERSION_10_8 1080
+#endif
+
+// 10.9 SDK
+
+#ifndef MAC_OS_X_VERSION_10_9
+#define MAC_OS_X_VERSION_10_9 1090
+#endif
+
+// 10.10 SDK
+
+#ifndef MAC_OS_X_VERSION_10_10
+#define MAC_OS_X_VERSION_10_10 101000
+#endif
+
+#endif  // CRASHPAD_COMPAT_MAC_AVAILABILITYMACROS_H_