Revert of [GN] Add JSON project writer

tools/gn/visibility.cc

Index: tools/gn/visibility.cc
diff --git a/tools/gn/visibility.cc b/tools/gn/visibility.cc
index b32586ce13e62537cca0796dccb82a840d8091a5..a61a5cd9c45f7effb57fd053be21ddaf29a6122e 100644
--- a/tools/gn/visibility.cc
+++ b/tools/gn/visibility.cc
@@ -4,10 +4,8 @@
 
 #include "tools/gn/visibility.h"
 
-#include "base/memory/ptr_util.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
-#include "base/values.h"
 #include "tools/gn/err.h"
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/item.h"
@@ -85,14 +83,6 @@
   return result;
 }
 
-std::unique_ptr<base::Value> Visibility::AsValue() const {
-  auto* res = new base::ListValue();
-  for (const auto& pattern : patterns_)
-    res->AppendString(pattern.Describe());
-
-  return WrapUnique(res);
-}
-
 // static
 bool Visibility::CheckItemVisibility(const Item* from,
                                      const Item* to,
@@ -103,7 +93,7 @@
         "The item " + from->label().GetUserVisibleName(false) + "\n"
         "can not depend on " + to_label + "\n"
         "because it is not in " + to_label + "'s visibility list: " +
-                   to->visibility().Describe(0, true));
+        to->visibility().Describe(0, true));
     return false;
   }
   return true;