Include implicit_cast.h at all users of it.

util/mach/exc_server_variants_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/exc_server_variants.h"
 
 #include <mach/mach.h>
 #include <string.h>
 
 #include "base/strings/stringprintf.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "test/mac/mach_errors.h"
 #include "test/mac/mach_multiprocess.h"
 #include "util/mac/mac_util.h"
 #include "util/mach/exception_behaviors.h"
 #include "util/mach/exception_types.h"
 #include "util/mach/mach_message.h"
+#include "util/misc/implicit_cast.h"
 
 namespace crashpad {
 namespace test {
 namespace {
 
 using testing::DefaultValue;
 using testing::Eq;
 using testing::Pointee;
 using testing::Return;
 
@@ skipping 1293 matching lines @@
     EXPECT_EQ(old_state[i], new_state[i]) << "i " << i;
   }
   for (size_t i = arraysize(old_state); i < arraysize(new_state); ++i) {
     EXPECT_EQ(0u, new_state[i]) << "i " << i;
   }
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace crashpad