Expand empty directories in GN to "."

tools/gn/ninja_binary_target_writer_unittest.cc

Index: tools/gn/ninja_binary_target_writer_unittest.cc
diff --git a/tools/gn/ninja_binary_target_writer_unittest.cc b/tools/gn/ninja_binary_target_writer_unittest.cc
index 20f9a8bee96d16788ce5d9cd77203537ca46e9d9..1d4bd0fc46cf4e724d3fc388322ba4f3a4e3f374 100644
--- a/tools/gn/ninja_binary_target_writer_unittest.cc
+++ b/tools/gn/ninja_binary_target_writer_unittest.cc
@@ -39,7 +39,7 @@ TEST(NinjaBinaryTargetWriter, SourceSet) {
         "cflags_cc =\n"
         "cflags_objc =\n"
         "cflags_objcc =\n"
-        "root_out_dir = \n"
+        "root_out_dir = .\n"
         "target_out_dir = obj/foo\n"
         "target_output_name = bar\n"
         "\n"
@@ -72,7 +72,7 @@ TEST(NinjaBinaryTargetWriter, SourceSet) {
         "cflags_cc =\n"
         "cflags_objc =\n"
         "cflags_objcc =\n"
-        "root_out_dir = \n"
+        "root_out_dir = .\n"
         "target_out_dir = obj/foo\n"
         "target_output_name = libshlib\n"
         "\n"
@@ -80,7 +80,7 @@ TEST(NinjaBinaryTargetWriter, SourceSet) {
         // Ordering of the obj files here should come out in the order
         // specified, with the target's first, followed by the source set's, in
         // order.
-        "build libshlib.so: solink obj/foo/bar.input1.o "
+        "build ./libshlib.so: solink obj/foo/bar.input1.o "
             "obj/foo/bar.input2.o ../../foo/input3.o ../../foo/input4.obj\n"
         "  ldflags =\n"
         "  libs =\n"
@@ -109,7 +109,7 @@ TEST(NinjaBinaryTargetWriter, SourceSet) {
         "cflags_cc =\n"
         "cflags_objc =\n"
         "cflags_objcc =\n"
-        "root_out_dir = \n"
+        "root_out_dir = .\n"
         "target_out_dir = obj/foo\n"
         "target_output_name = libstlib\n"
         "\n"
@@ -151,14 +151,14 @@ TEST(NinjaBinaryTargetWriter, ProductExtension) {
       "cflags_cc =\n"
       "cflags_objc =\n"
       "cflags_objcc =\n"
-      "root_out_dir = \n"
+      "root_out_dir = .\n"
       "target_out_dir = obj/foo\n"
       "target_output_name = libshlib\n"
       "\n"
       "build obj/foo/libshlib.input1.o: cxx ../../foo/input1.cc\n"
       "build obj/foo/libshlib.input2.o: cxx ../../foo/input2.cc\n"
       "\n"
-      "build libshlib.so.6: solink obj/foo/libshlib.input1.o "
+      "build ./libshlib.so.6: solink obj/foo/libshlib.input1.o "
           "obj/foo/libshlib.input2.o\n"
       "  ldflags =\n"
       "  libs =\n"
@@ -196,14 +196,14 @@ TEST(NinjaBinaryTargetWriter, EmptyProductExtension) {
       "cflags_cc =\n"
       "cflags_objc =\n"
       "cflags_objcc =\n"
-      "root_out_dir = \n"
+      "root_out_dir = .\n"
       "target_out_dir = obj/foo\n"
       "target_output_name = libshlib\n"
       "\n"
       "build obj/foo/libshlib.input1.o: cxx ../../foo/input1.cc\n"
       "build obj/foo/libshlib.input2.o: cxx ../../foo/input2.cc\n"
       "\n"
-      "build libshlib.so: solink obj/foo/libshlib.input1.o "
+      "build ./libshlib.so: solink obj/foo/libshlib.input1.o "
           "obj/foo/libshlib.input2.o\n"
       "  ldflags =\n"
       "  libs =\n"