Support private values in GN.

tools/gn/scope_unittest.cc

Index: tools/gn/scope_unittest.cc
diff --git a/tools/gn/scope_unittest.cc b/tools/gn/scope_unittest.cc
index 5585e50bd018226369d7d46ae6183965ca1197fa..da6813464cc5447ac7c8dce9bef9edadbb1ede29 100644
--- a/tools/gn/scope_unittest.cc
+++ b/tools/gn/scope_unittest.cc
@@ -36,6 +36,8 @@ TEST(Scope, NonRecursiveMergeTo) {
 
   Value old_value(&assignment, "hello");
   setup.scope()->SetValue("v", old_value, &assignment);
+  base::StringPiece private_var_name("_private");
+  setup.scope()->SetValue(private_var_name, old_value, &assignment);
 
   // Detect collisions of values' values.
   {
@@ -45,7 +47,8 @@ TEST(Scope, NonRecursiveMergeTo) {
 
     Err err;
     EXPECT_FALSE(setup.scope()->NonRecursiveMergeTo(
-        &new_scope, false, &assignment, "error", &err));
+        &new_scope, Scope::MergeOptions(),
+        &assignment, "error", &err));
     EXPECT_TRUE(err.has_error());
   }
 
@@ -56,8 +59,10 @@ TEST(Scope, NonRecursiveMergeTo) {
     new_scope.SetValue("v", new_value, &assignment);
 
     Err err;
+    Scope::MergeOptions options;
+    options.clobber_existing = true;
     EXPECT_TRUE(setup.scope()->NonRecursiveMergeTo(
-        &new_scope, true, &assignment, "error", &err));
+        &new_scope, options, &assignment, "error", &err));
     EXPECT_FALSE(err.has_error());
 
     const Value* found_value = new_scope.GetValue("v");
@@ -72,10 +77,36 @@ TEST(Scope, NonRecursiveMergeTo) {
     new_scope.SetValue("v", new_value, &assignment);
 
     Err err;
+    Scope::MergeOptions options;
+    options.clobber_existing = true;
     EXPECT_TRUE(setup.scope()->NonRecursiveMergeTo(
-        &new_scope, false, &assignment, "error", &err));
+        &new_scope, options, &assignment, "error", &err));
     EXPECT_FALSE(err.has_error());
   }
+
+  // Copy private values.
+  {
+    Scope new_scope(setup.settings());
+
+    Err err;
+    EXPECT_TRUE(setup.scope()->NonRecursiveMergeTo(
+        &new_scope, Scope::MergeOptions(), &assignment, "error", &err));
+    EXPECT_FALSE(err.has_error());
+    EXPECT_TRUE(new_scope.GetValue(private_var_name));
+  }
+
+  // Skip private values.
+  {
+    Scope new_scope(setup.settings());
+
+    Err err;
+    Scope::MergeOptions options;
+    options.copy_private_vars = false;
+    EXPECT_TRUE(setup.scope()->NonRecursiveMergeTo(
+        &new_scope, options, &assignment, "error", &err));
+    EXPECT_FALSE(err.has_error());
+    EXPECT_FALSE(new_scope.GetValue(private_var_name));
+  }
 }
 
 TEST(Scope, MakeClosure) {