Implement stack trace printing callback for v8

gin/public/v8_platform.h

Index: gin/public/v8_platform.h
diff --git a/gin/public/v8_platform.h b/gin/public/v8_platform.h
index 2eee1dd1b7b42b39a8277686c1169dfe599e6dac..896a21ec0ea8d4e0d793f3cf1bcb3202af29e203 100644
--- a/gin/public/v8_platform.h
+++ b/gin/public/v8_platform.h
@@ -53,6 +53,7 @@ class GIN_EXPORT V8Platform : public NON_EXPORTED_BASE(v8::Platform) {
 
   void AddTraceStateObserver(v8::Platform::TraceStateObserver*) override;
   void RemoveTraceStateObserver(v8::Platform::TraceStateObserver*) override;
+  StackTracePrinter GetStackTracePrinter() override;
 
  private:
   friend struct base::LazyInstanceTraitsBase<V8Platform>;