Add a new 'run_all_unittests' target in base

sync/sync.gyp

Index: sync/sync.gyp
diff --git a/sync/sync.gyp b/sync/sync.gyp
index f355761348d9ba07a05b34d67b25a0fc2ba4c1f6..43bc1031deb99984c11581616106ab21cd6804ad 100644
--- a/sync/sync.gyp
+++ b/sync/sync.gyp
@@ -250,7 +250,6 @@
       'suppress_wildcard': 1,
       'dependencies': [
         '../base/base.gyp:base',
-        '../base/base.gyp:test_support_base',
         '../testing/gmock.gyp:gmock',
         '../testing/gtest.gyp:gtest',
         'sync',
@@ -258,7 +257,6 @@
       ],
       'export_dependent_settings': [
         '../base/base.gyp:base',
-        '../base/base.gyp:test_support_base',
         '../testing/gmock.gyp:gmock',
         '../testing/gtest.gyp:gtest',
         'sync',
@@ -324,17 +322,11 @@
     #
     # TODO(akalin): Rename this to sync_unit_tests once we've moved
     # everything from chrome.gyp.
-    #
-    # TODO(akalin): Make base.gyp have a test_main target that
-    # includes run_all_unittests.cc and the possible tcmalloc
-    # dependency and use that everywhere.
     {
       'target_name': 'sync_unit_tests_canary',
       'type': 'executable',
-      'sources': [
-        '../base/test/run_all_unittests.cc',
-      ],
       'dependencies': [
+        '../base/base.gyp:run_all_unittests',
         'sync_tests',
       ],