[cros] Add RecursiveLock for CrOS implementation.

rlz/rlz.gyp

Index: rlz/rlz.gyp
diff --git a/rlz/rlz.gyp b/rlz/rlz.gyp
index 123eaa0a2396a6ea3325c13b41c81aa3fbd626a7..cdd66dc6d9e4810581816c2900f1f53abab553c2 100644
--- a/rlz/rlz.gyp
+++ b/rlz/rlz.gyp
@@ -42,6 +42,8 @@
         'lib/lib_values.cc',
         'lib/machine_id.cc',
         'lib/machine_id.h',
+        'lib/recursive_lock.cc',
+        'lib/recursive_lock.h',
         'lib/rlz_enums.h',
         'lib/rlz_lib.cc',
         'lib/rlz_lib.h',
@@ -92,6 +94,12 @@
             ],
           },
         }],
+        ['chromeos==0', {
+          'sources!': [
+            'lib/recursive_lock.cc',
+            'lib/recursive_lock.h',
+          ]
+        }],
       ],
     },
     {
@@ -110,6 +118,7 @@
         'lib/financial_ping_test.cc',
         'lib/lib_values_unittest.cc',
         'lib/machine_id_unittest.cc',
+        'lib/recursive_lock_unittest.cc',
         'lib/rlz_lib_test.cc',
         'lib/string_utils_unittest.cc',
         'test/rlz_test_helpers.cc',
@@ -122,6 +131,11 @@
           'dependencies': [
             '../net/net.gyp:net_test_support',
           ],
+        }],
+        ['chromeos==0', {
+          'sources!': [
+            'lib/recursive_lock_unittest.cc',
+          ],
         }]
       ],
     },