Create snapshot/mac and move some files from snapshot and util to there

snapshot/mac/exception_snapshot_mac.h

 // 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_SNAPSHOT_EXCEPTION_SNAPSHOT_MAC_H_
-#define CRASHPAD_SNAPSHOT_EXCEPTION_SNAPSHOT_MAC_H_
+#ifndef CRASHPAD_SNAPSHOT_MAC_EXCEPTION_SNAPSHOT_MAC_H_
+#define CRASHPAD_SNAPSHOT_MAC_EXCEPTION_SNAPSHOT_MAC_H_
 
 #include <mach/mach.h>
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "build/build_config.h"
 #include "snapshot/cpu_context.h"
 #include "snapshot/exception_snapshot.h"
@@ skipping 54 matching lines @@
   exception_type_t exception_;
   uint32_t exception_code_0_;
   InitializationStateDcheck initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(ExceptionSnapshotMac);
 };
 
 }  // namespace internal
 }  // namespace crashpad
 
-#endif  // CRASHPAD_SNAPSHOT_EXCEPTION_SNAPSHOT_MAC_H_
+#endif  // CRASHPAD_SNAPSHOT_MAC_EXCEPTION_SNAPSHOT_MAC_H_