Include implicit_cast.h at all users of it.

util/mach/child_port_server_test.cc

 // 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.
 
 #include "util/mach/child_port_server.h"
 
 #include <string.h>
 
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "util/mach/mach_extensions.h"
+#include "util/misc/implicit_cast.h"
 
 namespace crashpad {
 namespace test {
 namespace {
 
 using testing::Eq;
 using testing::Pointee;
 using testing::Return;
 
 // Fake Mach ports. These aren’t used as ports in these tests, they’re just used
@@ skipping 95 matching lines @@
       reinterpret_cast<mach_msg_header_t*>(&reply),
       &destroy_request));
   EXPECT_FALSE(destroy_request);
 
   reply.Verify();
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace crashpad