Fixed version of https://codereview.chromium.org/748793002

pylib/gyp/xcodeproj_file.py

Index: pylib/gyp/xcodeproj_file.py
diff --git a/pylib/gyp/xcodeproj_file.py b/pylib/gyp/xcodeproj_file.py
index 5cf4418e856ffa7eb0277141a6f2f1ae3e0e9c84..b593d7c36fa8671dbe3b321cc8c8a53f3b36cede 100644
--- a/pylib/gyp/xcodeproj_file.py
+++ b/pylib/gyp/xcodeproj_file.py
@@ -2749,11 +2749,12 @@ class PBXProject(XCContainerPortal):
     # The value of inherit_unique_symroot decides, if a configuration is assumed
     # to inherit a unique 'SYMROOT' attribute from its parent, if it doesn't
     # define an explicit value for 'SYMROOT'.
+    symroots = self._DefinedSymroots(target)
     for s in self._DefinedSymroots(target):
       if (s is not None and not self._IsUniqueSymrootForTarget(s) or
           s is None and not inherit_unique_symroot):
         return False
-    return True
+    return True if symroots else return inherit_unique_symroot
 
   def _DefinedSymroots(self, target):
     # Returns all values for the 'SYMROOT' attribute defined in all