Fix gyptest-sdkroot when oldest SDK is >= 10.8

test/mac/gyptest-sdkroot.py

Index: test/mac/gyptest-sdkroot.py
diff --git a/test/mac/gyptest-sdkroot.py b/test/mac/gyptest-sdkroot.py
index 20edd365d99312686599d3a67fe93938774553ab..711726ed87c5b2cfc52ac220dea1f281a9fc6044 100644
--- a/test/mac/gyptest-sdkroot.py
+++ b/test/mac/gyptest-sdkroot.py
@@ -17,22 +17,29 @@ import sys
 if sys.platform == 'darwin':
   test = TestGyp.TestGyp(formats=['ninja', 'make', 'xcode'])
 
+  def GetSDKPath(sdk):
+    """Return SDKROOT if the SDK version |sdk| is installed or empty string."""
+    DEVNULL = open(os.devnull, 'wb')
+    try:
+      proc = subprocess.Popen(
+          ['xcodebuild', '-version', '-sdk', 'macosx' + sdk, 'Path'],
+          stdout=subprocess.PIPE, stderr=DEVNULL)
+      return proc.communicate()[0].rstrip('\n')
+    finally:
+      DEVNULL.close()
+
+  def SelectSDK():
+    """Select the oldest SDK installed (greater than 10.6)."""
+    for sdk in ['10.6', '10.7', '10.8', '10.9']:
+      path = GetSDKPath(sdk)
+      if path:
+        return True, sdk, path
+    return False, '', ''
+
   # Make sure this works on the bots, which only have the 10.6 sdk, and on
-  # dev machines, which usually don't have the 10.6 sdk.
-  sdk = '10.6'
-  DEVNULL = open(os.devnull, 'wb')
-  proc = subprocess.Popen(['xcodebuild', '-version', '-sdk', 'macosx' + sdk],
-                          stdout=DEVNULL, stderr=DEVNULL)
-  proc.communicate()
-  DEVNULL.close()
-  if proc.returncode:
-    sdk = '10.7'
-
-  proc = subprocess.Popen(['xcodebuild', '-version',
-                           '-sdk', 'macosx' + sdk, 'Path'],
-                          stdout=subprocess.PIPE)
-  sdk_path = proc.communicate()[0].rstrip('\n')
-  if proc.returncode != 0:
+  # dev machines which usually don't have the 10.6 sdk.
+  sdk_found, sdk, sdk_path = SelectSDK()
+  if not sdk_found:
     test.fail_test()
 
   test.write('sdkroot/test.gyp', test.read('sdkroot/test.gyp') % sdk)