Move trace_event.h include from v8_platform.h to .cc file

gin/public/v8_platform.h

 // Copyright 2014 The Chromium 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 GIN_PUBLIC_V8_PLATFORM_H_
 #define GIN_PUBLIC_V8_PLATFORM_H_
 
 #include "base/compiler_specific.h"
 #include "base/lazy_instance.h"
 #include "base/macros.h"
-#include "base/trace_event/trace_event.h"
 #include "gin/gin_export.h"
 #include "v8/include/v8-platform.h"
 
 namespace gin {
 
 // A v8::Platform implementation to use with gin.
 class GIN_EXPORT V8Platform : public NON_EXPORTED_BASE(v8::Platform) {
  public:
   static V8Platform* Get();
 
@@ skipping 31 matching lines @@
 
   V8Platform();
   ~V8Platform() override;
 
   DISALLOW_COPY_AND_ASSIGN(V8Platform);
 };
 
 }  // namespace gin
 
 #endif  // GIN_PUBLIC_V8_PLATFORM_H_