Convert GN visibility to be a list.

tools/gn/visibility.cc

 // 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.
 
 #include "tools/gn/visibility.h"
 
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
 #include "tools/gn/err.h"
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/item.h"
 #include "tools/gn/label.h"
 #include "tools/gn/scope.h"
 #include "tools/gn/value.h"
 #include "tools/gn/variables.h"
 
 Visibility::Visibility() {
 }
 
 Visibility::~Visibility() {
 }
 
 bool Visibility::Set(const SourceDir& current_dir,
                      const Value& value,
                      Err* err) {
   patterns_.clear();
 
-  // Allow a single string to be passed in to make the common case (just one
-  // pattern) easier to specify.
-  if (value.type() == Value::STRING) {
-    patterns_.push_back(LabelPattern::GetPattern(current_dir, value, err));
-    return !err->has_error();
+  if (!value.VerifyTypeIs(Value::LIST, err)) {
+    CHECK(err->has_error());
+    return false;
   }
 
-  // If it's not a string, it should be a list of strings.
-  if (!value.VerifyTypeIs(Value::LIST, err))
-    return false;
-
   const std::vector<Value>& list = value.list_value();
   for (size_t i = 0; i < list.size(); i++) {
     patterns_.push_back(LabelPattern::GetPattern(current_dir, list[i], err));
     if (err->has_error())
       return false;
   }
   return true;
 }
 
 void Visibility::SetPublic() {
@@ skipping 59 matching lines @@
 
 // static
 bool Visibility::FillItemVisibility(Item* item, Scope* scope, Err* err) {
   const Value* vis_value = scope->GetValue(variables::kVisibility, true);
   if (vis_value)
     item->visibility().Set(scope->GetSourceDir(), *vis_value, err);
   else  // Default to public.
     item->visibility().SetPublic();
   return !err->has_error();
 }