Add TestGypXcodeNinja to run tests against the xcode-ninja generator

test/ninja/chained-dependency/gyptest-chained-dependency.py

Index: test/ninja/chained-dependency/gyptest-chained-dependency.py
diff --git a/test/ninja/chained-dependency/gyptest-chained-dependency.py b/test/ninja/chained-dependency/gyptest-chained-dependency.py
index 9fcd9a45d05c789038d241bf74b33093b2af6326..d8763f1d3db5b4b7a3aed37ba339ad1a4f1fb385 100755
--- a/test/ninja/chained-dependency/gyptest-chained-dependency.py
+++ b/test/ninja/chained-dependency/gyptest-chained-dependency.py
@@ -18,6 +18,10 @@ import TestGyp
 # - it relies on a ninja-specific output file path.
 
 test = TestGyp.TestGyp(formats=['ninja'])
+# xcode-ninja doesn't support building single object files by design.
+if test.format == 'xcode-ninja':
+  test.skip_test()
+
 test.run_gyp('chained-dependency.gyp')
 objext = '.obj' if sys.platform == 'win32' else '.o'
 test.build('chained-dependency.gyp',