Apply gn format with 'sources' sorting to src/

tools/gn/BUILD.gn

Index: tools/gn/BUILD.gn
diff --git a/tools/gn/BUILD.gn b/tools/gn/BUILD.gn
index e0de60e1194ea0c0274cde6141cca861c9738e6a..bc37bc765894afbbe7356bcffcdc4b5f82b1b1ee 100644
--- a/tools/gn/BUILD.gn
+++ b/tools/gn/BUILD.gn
@@ -55,9 +55,6 @@ static_library("gn_lib") {
     "exec_process.h",
     "filesystem_utils.cc",
     "filesystem_utils.h",
-    "functions.cc",
-    "functions.h",
-    "functions_target.cc",
     "function_exec_script.cc",
     "function_foreach.cc",
     "function_get_label_info.cc",
@@ -71,6 +68,9 @@ static_library("gn_lib") {
     "function_template.cc",
     "function_toolchain.cc",
     "function_write_file.cc",
+    "functions.cc",
+    "functions.h",
+    "functions_target.cc",
     "group_target_generator.cc",
     "group_target_generator.h",
     "header_checker.cc",
@@ -104,12 +104,12 @@ static_library("gn_lib") {
     "ninja_copy_target_writer.h",
     "ninja_group_target_writer.cc",
     "ninja_group_target_writer.h",
-    "ninja_utils.cc",
-    "ninja_utils.h",
     "ninja_target_writer.cc",
     "ninja_target_writer.h",
     "ninja_toolchain_writer.cc",
     "ninja_toolchain_writer.h",
+    "ninja_utils.cc",
+    "ninja_utils.h",
     "ninja_writer.cc",
     "ninja_writer.h",
     "operators.cc",
@@ -163,9 +163,9 @@ static_library("gn_lib") {
     "token.cc",
     "token.h",
     "tokenizer.cc",
+    "tokenizer.h",
     "tool.cc",
     "tool.h",
-    "tokenizer.h",
     "toolchain.cc",
     "toolchain.h",
     "trace.cc",