Make rebase_path("//foo", "//foo") resolve to "." (not "../foo")

tools/gn/function_rebase_path_unittest.cc

Index: tools/gn/function_rebase_path_unittest.cc
diff --git a/tools/gn/function_rebase_path_unittest.cc b/tools/gn/function_rebase_path_unittest.cc
index 4b09790fa7ebe18910872058ea9a555d0bde707c..d89b56f616b4252cf0eb0085403746c3c7961756 100644
--- a/tools/gn/function_rebase_path_unittest.cc
+++ b/tools/gn/function_rebase_path_unittest.cc
@@ -51,9 +51,7 @@ TEST(RebasePath, Strings) {
   EXPECT_EQ("foo/", RebaseOne(scope, "//foo/", "//", "//"));
   EXPECT_EQ("../../foo/bar", RebaseOne(scope, "//foo/bar", "//out/Debug", "."));
   EXPECT_EQ("./", RebaseOne(scope, "//foo/", "//foo/", "//"));
-  // Thie one is technically correct but could be simplified to "." if
-  // necessary.
-  EXPECT_EQ("../foo", RebaseOne(scope, "//foo", "//foo", "//"));
+  EXPECT_EQ(".", RebaseOne(scope, "//foo", "//foo", "//"));
 
   // Test slash conversion.
   EXPECT_EQ("foo/bar", RebaseOne(scope, "foo/bar", ".", "."));