[inspector] Build inspector under v8_enable_inspector build flag.

src/inspector/V8StackTraceImpl.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_V8STACKTRACEIMPL_H_
 #define V8_INSPECTOR_V8STACKTRACEIMPL_H_
 
 #include "src/inspector/Allocator.h"
 #include "src/inspector/protocol/Forward.h"
 #include "src/inspector/protocol/Runtime.h"
-#include "src/inspector/public/V8StackTrace.h"
+
+#include "include/v8-inspector.h"
 
 #include <vector>
 
 namespace v8_inspector {
 
 class TracedValue;
 class V8Debugger;
 
 // Note: async stack trace may have empty top stack with non-empty tail to
 // indicate
@@ skipping 67 matching lines @@
 
   int m_contextGroupId;
   String16 m_description;
   std::vector<Frame> m_frames;
   std::unique_ptr<V8StackTraceImpl> m_parent;
 };
 
 }  // namespace v8_inspector
 
 #endif  // V8_INSPECTOR_V8STACKTRACEIMPL_H_