[inspector] change implementation file extension from cpp to cc

src/inspector/protocol-platform.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_INSPECTOR_PROTOCOLPLATFORM_H_
 #define V8_INSPECTOR_PROTOCOLPLATFORM_H_
 
 #include <memory>
 
 #include "src/base/logging.h"
 
 namespace v8_inspector {
 
 template <typename T>
 std::unique_ptr<T> wrapUnique(T* ptr) {
   return std::unique_ptr<T>(ptr);
 }
 
 }  // namespace v8_inspector
 
 #endif  // V8_INSPECTOR_PROTOCOLPLATFORM_H_