Add annotations to the policy template metafile

The annotations include a list of supported platforms for each policy. Depending on this, only the supported policies are written for each template type.

BUG=54665
TEST=PolicyTemplateGeneratorUnittest.testPolicyFiltering, {Adm,Plist,PlistStrings}WriterUnittest.testNonSupportedPolicy, {Admx,Adml}WriterUnittest.testPlatform

Review URL: http://codereview.chromium.org/3303027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@59483 0039d316-1c4b-4281-b951-d872f2087c98

14 files changed, 321 insertions, 44 deletions

diff --git a/tools/grit/grit/format/policy_templates/policy_template_generator.py b/tools/grit/grit/format/policy_templates/policy_template_generator.py
index 165cc91..e4fbbfe 100644
--- a/tools/grit/grit/format/policy_templates/policy_template_generator.py
+++ b/tools/grit/grit/format/policy_templates/policy_template_generator.py
@@ -109,6 +109,24 @@ class PolicyTemplateGenerator:
         for policy in group['policies']:
           self._AddMessagesToPolicy(policy)
 
+  def _GetPoliciesForWriter(self, template_writer, group):
+    '''Filters the list of policies in a group for a writer.
+
+    Args:
+      template_writer: The writer object.
+      group: The dictionary of the policy group.
+
+    Returns: The list of policies of the policy group that are compatible
+      with the writer.
+    '''
+    if not 'policies' in group:
+      return []
+    result = []
+    for policy in group['policies']:
+      if template_writer.IsPolicySupported(policy):
+        result.append(policy)
+    return result
+
   def GetTemplateText(self, template_writer):
     '''Generates the text of the template from the arguments given
     to the constructor, using a given TemplateWriter.
@@ -123,10 +141,12 @@ class PolicyTemplateGenerator:
     template_writer.Prepare()
     template_writer.BeginTemplate()
     for group in self._policy_groups:
-      template_writer.BeginPolicyGroup(group)
-      if 'policies' in group:
-        for policy in group['policies']:
+      policies = self._GetPoliciesForWriter(template_writer, group)
+      if policies:
+        # Only write nonempty groups.
+        template_writer.BeginPolicyGroup(group)
+        for policy in policies:
           template_writer.WritePolicy(policy)
-      template_writer.EndPolicyGroup()
+        template_writer.EndPolicyGroup()
     template_writer.EndTemplate()
     return template_writer.GetTemplateText()
diff --git a/tools/grit/grit/format/policy_templates/policy_template_generator_unittest.py b/tools/grit/grit/format/policy_templates/policy_template_generator_unittest.py
index 61debe5..aab761b 100644
--- a/tools/grit/grit/format/policy_templates/policy_template_generator_unittest.py
+++ b/tools/grit/grit/format/policy_templates/policy_template_generator_unittest.py
@@ -3,10 +3,16 @@
 # found in the LICENSE file.
 
 
+import os
+import sys
+if __name__ == '__main__':
+  sys.path.append(os.path.join(os.path.dirname(sys.argv[0]), '../../..'))
+
 import unittest
 
-from policy_template_generator import PolicyTemplateGenerator
-from writers.mock_writer import MockWriter
+from grit.format.policy_templates import policy_template_generator
+from grit.format.policy_templates.writers import mock_writer
+from grit.format.policy_templates.writers import template_writer
 
 
 class PolicyTemplateGeneratorUnittest(unittest.TestCase):
@@ -30,7 +36,9 @@ class PolicyTemplateGeneratorUnittest(unittest.TestCase):
         mock_writer.MockWriter.
     '''
     writer.tester = self
-    policy_generator = PolicyTemplateGenerator(messages, policy_groups)
+    policy_generator = policy_template_generator.PolicyTemplateGenerator(
+        messages,
+        policy_groups)
     res = policy_generator.GetTemplateText(writer)
     writer.Test()
     return res
@@ -38,7 +46,7 @@ class PolicyTemplateGeneratorUnittest(unittest.TestCase):
   def testSequence(self):
     # Test the sequence of invoking the basic PolicyWriter operations,
     # in case of empty input data structures.
-    class LocalMockWriter(MockWriter):
+    class LocalMockWriter(mock_writer.MockWriter):
       def __init__(self):
         self.log = 'init;'
       def Prepare(self):
@@ -57,8 +65,7 @@ class PolicyTemplateGeneratorUnittest(unittest.TestCase):
     self.assertEquals(result, 'writer_result_string')
 
   def testEmptyGroups(self):
-    # Test that in case of three empty policy groups, each one is passed to
-    # the writer.
+    # Test that empty policy groups are not passed to the writer.
     messages_mock = {
       'IDS_POLICY_GROUP_GROUP1_CAPTION': None,
       'IDS_POLICY_GROUP_GROUP1_DESC': None,
@@ -68,24 +75,48 @@ class PolicyTemplateGeneratorUnittest(unittest.TestCase):
       'IDS_POLICY_GROUP_GROUP3_DESC': None,
     }
     policies_mock = [
-      {'name': 'Group1', 'tag': 'T1'},
-      {'name': 'Group2', 'tag': 'T2'},
-      {'name': 'Group3', 'tag': 'T3'},
+      {'name': 'Group1', 'policies': []},
+      {'name': 'Group2', 'policies': []},
+      {'name': 'Group3', 'policies': []},
     ]
-    class LocalMockWriter(MockWriter):
+    class LocalMockWriter(mock_writer.MockWriter):
       def __init__(self):
         self.log = ''
-        self.set = set()
       def BeginPolicyGroup(self, group):
         self.log += '['
-        self.set.add ( (group['name'], group['tag']) )
       def EndPolicyGroup(self):
         self.log += ']'
       def Test(self):
-        self.tester.assertEquals(self.log, '[][][]')
-        self.tester.assertEquals(
-          self.set,
-          set([('Group1', 'T1'), ('Group2', 'T2'), ('Group3', 'T3')]))
+        self.tester.assertEquals(self.log, '')
+    self.do_test(messages_mock, policies_mock, LocalMockWriter())
+
+  def testGroups(self):
+    # Test that policy groups are passed to the writer in the correct order.
+    messages_mock = {
+      'IDS_POLICY_GROUP_GROUP1_CAPTION': None,
+      'IDS_POLICY_GROUP_GROUP1_DESC': None,
+      'IDS_POLICY_GROUP_GROUP2_CAPTION': None,
+      'IDS_POLICY_GROUP_GROUP2_DESC': None,
+      'IDS_POLICY_GROUP_GROUP3_CAPTION': None,
+      'IDS_POLICY_GROUP_GROUP3_DESC': None,
+      'IDS_POLICY_TAG1_CAPTION': None,
+      'IDS_POLICY_TAG2_CAPTION': None,
+      'IDS_POLICY_TAG3_CAPTION': None,
+    }
+    policies_mock = [
+      {'name': 'Group1', 'policies': [{'name': 'TAG1', 'type': 'mock'}]},
+      {'name': 'Group2', 'policies': [{'name': 'TAG2', 'type': 'mock'}]},
+      {'name': 'Group3', 'policies': [{'name': 'TAG3', 'type': 'mock'}]},
+    ]
+    class LocalMockWriter(mock_writer.MockWriter):
+      def __init__(self):
+        self.log = ''
+      def BeginPolicyGroup(self, group):
+        self.log += '[' + group['policies'][0]['name']
+      def EndPolicyGroup(self):
+        self.log += ']'
+      def Test(self):
+        self.tester.assertEquals(self.log, '[TAG1][TAG2][TAG3]')
     self.do_test(messages_mock, policies_mock, LocalMockWriter())
 
   def testGroupTexts(self):
@@ -100,7 +131,7 @@ class PolicyTemplateGeneratorUnittest(unittest.TestCase):
       {'name': 'Group1'},
       {'name': 'Group2'},
     ]
-    class LocalMockWriter(MockWriter):
+    class LocalMockWriter(mock_writer.MockWriter):
       def BeginPolicyGroup(self, group):
         if group['name'] == 'Group1':
           self.tester.assertEquals(group['caption'], 'string1')
@@ -113,7 +144,7 @@ class PolicyTemplateGeneratorUnittest(unittest.TestCase):
     self.do_test(messages_mock, policy_groups_mock, LocalMockWriter())
 
   def testPolicies(self):
-    # Test that policies are passed correctly to the writer.
+    # Test that policies are passed to the writer in the correct order.
     messages_mock = {
       'IDS_POLICY_GROUP_GROUP1_CAPTION': None,
       'IDS_POLICY_GROUP_GROUP1_DESC': None,
@@ -138,21 +169,21 @@ class PolicyTemplateGeneratorUnittest(unittest.TestCase):
         ]
       }
     ]
-    class LocalMockWriter(MockWriter):
+    class LocalMockWriter(mock_writer.MockWriter):
       def __init__(self):
         self.policy_name = None
-        self.policy_set = set()
+        self.policy_list = []
       def BeginPolicyGroup(self, group):
         self.group = group;
       def EndPolicyGroup(self):
         self.group = None
-      def WritePolicy(self, group):
-        self.tester.assertEquals(group['name'][0:6], self.group['name'])
-        self.policy_set.add(group['name'])
+      def WritePolicy(self, policy):
+        self.tester.assertEquals(policy['name'][0:6], self.group['name'])
+        self.policy_list.append(policy['name'])
       def Test(self):
         self.tester.assertEquals(
-          self.policy_set,
-          set(['Group1Policy1', 'Group1Policy2', 'Group2Policy3']))
+          self.policy_list,
+          ['Group1Policy1', 'Group1Policy2', 'Group2Policy3'])
     self.do_test(messages_mock, policy_groups_mock, LocalMockWriter())
 
   def testPolicyTexts(self):
@@ -174,7 +205,7 @@ class PolicyTemplateGeneratorUnittest(unittest.TestCase):
         ]
       }
     ]
-    class LocalMockWriter(MockWriter):
+    class LocalMockWriter(mock_writer.MockWriter):
       def WritePolicy(self, policy):
         if policy['name'] == 'Policy1':
           self.tester.assertEquals(policy['caption'], 'string1')
@@ -211,13 +242,79 @@ class PolicyTemplateGeneratorUnittest(unittest.TestCase):
         }]
       }
     ]
-    class LocalMockWriter(MockWriter):
+    class LocalMockWriter(mock_writer.MockWriter):
       def WritePolicy(self, policy):
         self.tester.assertEquals(policy['items'][0]['caption'], 'string1')
         self.tester.assertEquals(policy['items'][1]['caption'], 'string2')
         self.tester.assertEquals(policy['items'][2]['caption'], 'string3')
     self.do_test(messages_mock, policy_groups_mock, LocalMockWriter())
 
+  def testPolicyFiltering(self):
+    # Test that policies are filtered correctly based on their annotations.
+    messages_mock = {
+      'IDS_POLICY_GROUP_GROUP1_CAPTION': None,
+      'IDS_POLICY_GROUP_GROUP1_DESC': None,
+      'IDS_POLICY_GROUP_GROUP2_CAPTION': None,
+      'IDS_POLICY_GROUP_GROUP2_DESC': None,
+      'IDS_POLICY_GROUP1POLICY1_CAPTION': None,
+      'IDS_POLICY_GROUP1POLICY2_CAPTION': None,
+      'IDS_POLICY_GROUP2POLICY3_CAPTION': None,
+    }
+    policy_groups_mock = [{
+      'name': 'Group1',
+      'policies': [
+        {
+          'name': 'Group1Policy1',
+          'type': 'string',
+          'annotations': {'platforms': ['aaa', 'bbb', 'ccc']}
+        },
+        {
+          'name': 'Group1Policy2',
+          'type': 'string',
+          'annotations': {'platforms': ['ddd']}
+        },
+      ]
+    },{
+      'name': 'Group2',
+      'policies': [
+        {
+          'name': 'Group2Policy3',
+          'type': 'string',
+          'annotations': {'platforms': ['eee']}
+        },
+      ]
+    }]
+    class LocalMockWriter(mock_writer.MockWriter):
+      def __init__(self, platforms, expected_list):
+        self.platforms = platforms
+        self.expected_list = expected_list
+        self.policy_name = None
+        self.result_list = []
+      def BeginPolicyGroup(self, group):
+        self.group = group;
+        self.result_list.append('begin_' + group['name'])
+      def EndPolicyGroup(self):
+        self.group = None
+      def WritePolicy(self, policy):
+        self.tester.assertEquals(policy['name'][0:6], self.group['name'])
+        self.result_list.append(policy['name'])
+      def IsPolicySupported(self, policy):
+        # Call the original (non-mock) implementation of this method.
+        return template_writer.TemplateWriter.IsPolicySupported(self, policy)
+      def Test(self):
+        self.tester.assertEquals(
+          self.result_list,
+          self.expected_list)
+    self.do_test(
+        messages_mock,
+        policy_groups_mock,
+        LocalMockWriter(['eee'], ['begin_Group2', 'Group2Policy3']))
+    self.do_test(
+        messages_mock,
+        policy_groups_mock,
+        LocalMockWriter(
+            ['ddd', 'bbb'],
+            ['begin_Group1', 'Group1Policy1', 'Group1Policy2']))
 
 if __name__ == '__main__':
   unittest.main()
diff --git a/tools/grit/grit/format/policy_templates/writers/adm_writer.py b/tools/grit/grit/format/policy_templates/writers/adm_writer.py
index 68987fb..e3a079f 100644
--- a/tools/grit/grit/format/policy_templates/writers/adm_writer.py
+++ b/tools/grit/grit/format/policy_templates/writers/adm_writer.py
@@ -6,12 +6,12 @@
 from grit.format.policy_templates.writers import template_writer
 
 
-def GetWriter(info, messages):
+def GetWriter(config, messages):
   '''Factory method for creating AdmWriter objects.
   See the constructor of TemplateWriter for description of
   arguments.
   '''
-  return AdmWriter(info, messages)
+  return AdmWriter(['win'], config, messages)
 
 
 class AdmWriter(template_writer.TemplateWriter):
diff --git a/tools/grit/grit/format/policy_templates/writers/adm_writer_unittest.py b/tools/grit/grit/format/policy_templates/writers/adm_writer_unittest.py
index ec47e33..c82abcb 100644
--- a/tools/grit/grit/format/policy_templates/writers/adm_writer_unittest.py
+++ b/tools/grit/grit/format/policy_templates/writers/adm_writer_unittest.py
@@ -71,6 +71,7 @@ chromium="Chromium"'''
             'policies': [{
               'name': 'MainPolicy',
               'type': 'main',
+              'annotations': {'platforms': ['win']}
             }],
           },
         ],
@@ -119,6 +120,7 @@ MainGroup_Explain="Description of main."'''
             'policies': [{
               'name': 'StringPolicy',
               'type': 'string',
+              'annotations': {'platforms': ['win']}
             }],
           },
         ],
@@ -172,7 +174,8 @@ StringPolicy_Part="Caption of policy."
               'items': [
                 {'name': 'ProxyServerDisabled', 'value': '0'},
                 {'name': 'ProxyServerAutoDetect', 'value': '1'},
-              ]
+              ],
+              'annotations': {'platforms': ['win']}
             }],
           },
         ],
@@ -234,6 +237,7 @@ ProxyServerAutoDetect_DropDown="Option2"
             'policies': [{
               'name': 'ListPolicy',
               'type': 'list',
+              'annotations': {'platforms': ['win']}
             }],
           },
         ],
@@ -275,6 +279,42 @@ ListPolicy_Part="Caption of list policy."
 '''
     self.CompareOutputs(output, expected_output)
 
+  def testNonSupportedPolicy(self):
+    # Tests a policy that is not supported on Windows, so it shouldn't
+    # be included in the ADM file.
+    grd = self.PrepareTest('''
+      {
+        'policy_groups': [
+          {
+            'name': 'NonWinGroup',
+            'policies': [{
+              'name': 'NonWinPolicy',
+              'type': 'list',
+              'annotations': {'platforms': ['linux', 'mac']}
+            }],
+          },
+        ],
+        'placeholders': [],
+      }''', '''
+        <messages>
+          <message name="IDS_POLICY_GROUP_NONWINGROUP_CAPTION">Group caption.</message>
+          <message name="IDS_POLICY_GROUP_NONWINGROUP_DESC">Group description.</message>
+          <message name="IDS_POLICY_NONWINPOLICY_CAPTION">Caption of list policy.</message>
+          <message name="IDS_POLICY_WIN_SUPPORTED_WINXPSP2">At least Windows 3.16</message>
+        </messages>
+      ''')
+    output = self.GetOutput(grd, 'fr', {'_chromium' : '1'}, 'adm', 'en')
+    expected_output = '''CLASS MACHINE
+  CATEGORY !!chromium
+    KEYNAME "Software\\Policies\\Chromium"
+
+  END CATEGORY
+
+[Strings]
+SUPPORTED_WINXPSP2="At least Windows 3.16"
+chromium="Chromium"
+'''
+    self.CompareOutputs(output, expected_output)
 
 if __name__ == '__main__':
   unittest.main()
diff --git a/tools/grit/grit/format/policy_templates/writers/adml_writer.py b/tools/grit/grit/format/policy_templates/writers/adml_writer.py
index fa40104..c6af9f1 100644
--- a/tools/grit/grit/format/policy_templates/writers/adml_writer.py
+++ b/tools/grit/grit/format/policy_templates/writers/adml_writer.py
@@ -6,12 +6,12 @@ from xml.dom import minidom
 from grit.format.policy_templates.writers import xml_formatted_writer
 
 
-def GetWriter(info, messages):
+def GetWriter(config, messages):
   '''Factory method for instanciating the ADMLWriter. Every Writer needs a
   GetWriter method because the TemplateFormatter uses this method to
   instantiate a Writer.
   '''
-  return ADMLWriter(info, messages)
+  return ADMLWriter(['win'], config, messages)
 
 
 class ADMLWriter(xml_formatted_writer.XMLFormattedWriter):
diff --git a/tools/grit/grit/format/policy_templates/writers/adml_writer_unittest.py b/tools/grit/grit/format/policy_templates/writers/adml_writer_unittest.py
index e345ae0..c21ab65 100644
--- a/tools/grit/grit/format/policy_templates/writers/adml_writer_unittest.py
+++ b/tools/grit/grit/format/policy_templates/writers/adml_writer_unittest.py
@@ -31,7 +31,7 @@ class AdmlWriterTest(xml_writer_base_unittest.XmlWriterBaseTest):
     messages = {
       'IDS_POLICY_WIN_SUPPORTED_WINXPSP2': 'Supported on Test OS or higher'
     }
-    self.writer = adml_writer.ADMLWriter(config, messages)
+    self.writer = adml_writer.GetWriter(config, messages)
     self.writer.Prepare()
 
   def _InitWriterForAddingPolicyGroups(self, writer):
@@ -181,6 +181,19 @@ class AdmlWriterTest(xml_writer_base_unittest.XmlWriterBaseTest):
         '</listBox>')
     self.AssertXMLEquals(output, expected_output)
 
+  def testPlatform(self):
+    # Test that the writer correctly chooses policies of platform Windows.
+    self.assertTrue(self.writer.IsPolicySupported({
+      'annotations': {
+        'platforms': ['win', 'zzz', 'aaa']
+      }
+    }))
+    self.assertFalse(self.writer.IsPolicySupported({
+      'annotations': {
+        'platforms': ['mac', 'linux', 'aaa']
+      }
+    }))
+
 
 if __name__ == '__main__':
   unittest.main()
diff --git a/tools/grit/grit/format/policy_templates/writers/admx_writer.py b/tools/grit/grit/format/policy_templates/writers/admx_writer.py
index 5eb67ca..e266944 100644
--- a/tools/grit/grit/format/policy_templates/writers/admx_writer.py
+++ b/tools/grit/grit/format/policy_templates/writers/admx_writer.py
@@ -11,7 +11,7 @@ def GetWriter(config, messages):
   GetWriter method because the TemplateFormatter uses this method to
   instantiate a Writer.
   '''
-  return ADMXWriter(config, messages)
+  return ADMXWriter(['win'], config, messages)
 
 
 class ADMXWriter(xml_formatted_writer.XMLFormattedWriter):
diff --git a/tools/grit/grit/format/policy_templates/writers/admx_writer_unittest.py b/tools/grit/grit/format/policy_templates/writers/admx_writer_unittest.py
index 532733c..634d0b5 100644
--- a/tools/grit/grit/format/policy_templates/writers/admx_writer_unittest.py
+++ b/tools/grit/grit/format/policy_templates/writers/admx_writer_unittest.py
@@ -40,7 +40,7 @@ class AdmxWriterTest(xml_writer_base_unittest.XmlWriterBaseTest):
     }
     # Grit messages.
     messages = {}
-    self.writer = admx_writer.ADMXWriter(config, messages)
+    self.writer = admx_writer.GetWriter(config, messages)
     self.writer.Prepare()
 
   def testEmpty(self):
@@ -155,6 +155,19 @@ class AdmxWriterTest(xml_writer_base_unittest.XmlWriterBaseTest):
 
     self.AssertXMLEquals(output, expected_output)
 
+  def testPlatform(self):
+    # Test that the writer correctly chooses policies of platform Windows.
+    self.assertTrue(self.writer.IsPolicySupported({
+      'annotations': {
+        'platforms': ['win', 'zzz', 'aaa']
+      }
+    }))
+    self.assertFalse(self.writer.IsPolicySupported({
+      'annotations': {
+        'platforms': ['mac', 'linux', 'aaa']
+      }
+    }))
+
 
 if __name__ == '__main__':
   unittest.main()
diff --git a/tools/grit/grit/format/policy_templates/writers/mock_writer.py b/tools/grit/grit/format/policy_templates/writers/mock_writer.py
index fd1f8c9..97b9e47 100644
--- a/tools/grit/grit/format/policy_templates/writers/mock_writer.py
+++ b/tools/grit/grit/format/policy_templates/writers/mock_writer.py
@@ -34,5 +34,8 @@ class MockWriter(TemplateWriter):
   def GetTemplateText(self):
     pass
 
+  def IsPolicySupported(self, policy):
+    return True
+
   def Test(self):
     pass
diff --git a/tools/grit/grit/format/policy_templates/writers/plist_strings_writer.py b/tools/grit/grit/format/policy_templates/writers/plist_strings_writer.py
index 51c43e9..faec9f8 100644
--- a/tools/grit/grit/format/policy_templates/writers/plist_strings_writer.py
+++ b/tools/grit/grit/format/policy_templates/writers/plist_strings_writer.py
@@ -11,7 +11,7 @@ def GetWriter(config, messages):
   See the constructor of TemplateWriter for description of
   arguments.
   '''
-  return PListStringsWriter(config, messages)
+  return PListStringsWriter(['mac'], config, messages)
 
 
 class PListStringsWriter(template_writer.TemplateWriter):
diff --git a/tools/grit/grit/format/policy_templates/writers/plist_strings_writer_unittest.py b/tools/grit/grit/format/policy_templates/writers/plist_strings_writer_unittest.py
index d8b3506..b604511 100644
--- a/tools/grit/grit/format/policy_templates/writers/plist_strings_writer_unittest.py
+++ b/tools/grit/grit/format/policy_templates/writers/plist_strings_writer_unittest.py
@@ -57,6 +57,7 @@ Chromium.pfm_description = "Chromium preferen\\"ces";
             'policies': [{
               'name': 'MainPolicy',
               'type': 'main',
+              'annotations': {'platforms': ['mac']},
             }],
           },
         ],
@@ -93,6 +94,7 @@ MainPolicy.pfm_description = "Title of main.";
             'policies': [{
               'name': 'StringPolicy',
               'type': 'string',
+              'annotations': {'platforms': ['mac']},
             }],
           },
         ],
@@ -133,7 +135,8 @@ StringPolicy.pfm_description = "Description of group.\\nWith a newline.";
               'items': [
                 {'name': 'ProxyServerDisabled', 'value': '0'},
                 {'name': 'ProxyServerAutoDetect', 'value': '1'},
-              ]
+              ],
+              'annotations': {'platforms': ['mac']},
             }],
           },
         ],
@@ -163,6 +166,42 @@ EnumPolicy.pfm_description = "0 - Option1\\n1 - Option2\\nDescription of policy.
         '''
     self.assertEquals(output.strip(), expected_output.strip())
 
+  def testNonSupportedPolicy(self):
+    # Tests a policy that is not supported on Mac, so its strings shouldn't
+    # be included in the plist string table.
+    grd = self.PrepareTest('''
+      {
+        'policy_groups': [
+          {
+            'name': 'NonMacGroup',
+            'policies': [{
+              'name': 'NonMacPolicy',
+              'type': 'string',
+              'annotations': {'platforms': ['win', 'linux']},
+            }],
+          },
+        ],
+        'placeholders': [],
+      }''', '''
+        <messages>
+          <message name="IDS_POLICY_GROUP_NONMACGROUP_CAPTION">Caption of group.</message>
+          <message name="IDS_POLICY_GROUP_NONMACGROUP_DESC">Description of group.</message>
+          <message name="IDS_POLICY_NONMACPOLICY_CAPTION">Caption of policy.</message>
+          <message name="IDS_POLICY_MAC_CHROME_PREFERENCES">$1 preferences</message>
+        </messages>
+      ''' )
+    output = self.GetOutput(
+        grd,
+        'fr',
+        {'_google_chrome': '1', 'mac_bundle_id': 'com.example.Test2'},
+        'plist_strings',
+        'en')
+    expected_output = \
+'''Google Chrome.pfm_title = "Google Chrome";
+Google Chrome.pfm_description = "Google Chrome preferences";
+        '''
+    self.assertEquals(output.strip(), expected_output.strip())
+
 
 if __name__ == '__main__':
   unittest.main()
diff --git a/tools/grit/grit/format/policy_templates/writers/plist_writer.py b/tools/grit/grit/format/policy_templates/writers/plist_writer.py
index aff1d05..37deb94 100644
--- a/tools/grit/grit/format/policy_templates/writers/plist_writer.py
+++ b/tools/grit/grit/format/policy_templates/writers/plist_writer.py
@@ -12,7 +12,7 @@ def GetWriter(config, messages):
   See the constructor of TemplateWriter for description of
   arguments.
   '''
-  return PListWriter(config, messages)
+  return PListWriter(['mac'], config, messages)
 
 
 class PListWriter(xml_formatted_writer.XMLFormattedWriter):
diff --git a/tools/grit/grit/format/policy_templates/writers/plist_writer_unittest.py b/tools/grit/grit/format/policy_templates/writers/plist_writer_unittest.py
index 35af4a6..157a258 100644
--- a/tools/grit/grit/format/policy_templates/writers/plist_writer_unittest.py
+++ b/tools/grit/grit/format/policy_templates/writers/plist_writer_unittest.py
@@ -87,6 +87,7 @@ class PListWriterUnittest(writer_unittest_common.WriterUnittestCommon):
             'policies': [{
               'name': 'MainPolicy',
               'type': 'main',
+              'annotations': {'platforms': ['mac']},
             }],
           },
         ],
@@ -132,6 +133,7 @@ class PListWriterUnittest(writer_unittest_common.WriterUnittestCommon):
             'policies': [{
               'name': 'StringPolicy',
               'type': 'string',
+              'annotations': {'platforms': ['mac']},
             }],
           },
         ],
@@ -182,7 +184,8 @@ class PListWriterUnittest(writer_unittest_common.WriterUnittestCommon):
               'items': [
                 {'name': 'ProxyServerDisabled', 'value': '0'},
                 {'name': 'ProxyServerAutoDetect', 'value': '1'},
-              ]
+              ],
+              'annotations': {'platforms': ['mac']},
             }],
           },
         ],
@@ -227,6 +230,39 @@ class PListWriterUnittest(writer_unittest_common.WriterUnittestCommon):
     </array>''')
     self.assertEquals(output.strip(), expected_output.strip())
 
+  def testNonSupportedPolicy(self):
+    # Tests a policy that is not supported on Mac, so it shouldn't
+    # be included in the plist file.
+    grd = self.PrepareTest('''
+      {
+        'policy_groups': [
+          {
+            'name': 'NonMacGroup',
+            'policies': [{
+              'name': 'NonMacPolicy',
+              'type': 'string',
+              'annotations': {'platforms': ['win', 'linux']},
+            }],
+          },
+        ],
+        'placeholders': [],
+      }''', '''
+        <messages>
+          <message name="IDS_POLICY_GROUP_NONMACGROUP_CAPTION">This is not tested here. (1)</message>
+          <message name="IDS_POLICY_GROUP_NONMACGROUP_DESC">This is not tested here. (2)</message>
+          <message name="IDS_POLICY_NONMACPOLICY_CAPTION">This is not tested here. (3)</message>
+        </messages>
+      ''' )
+    output = self.GetOutput(
+        grd,
+        'fr',
+        {'_google_chrome': '1', 'mac_bundle_id': 'com.example.Test2'},
+        'plist',
+        'en')
+    expected_output = \
+        self._GetExpectedOutputs('Google Chrome', 'com.example.Test2', '''<array/>''')
+    self.assertEquals(output.strip(), expected_output.strip())
+
 
 if __name__ == '__main__':
   unittest.main()
diff --git a/tools/grit/grit/format/policy_templates/writers/template_writer.py b/tools/grit/grit/format/policy_templates/writers/template_writer.py
index 7894d06..ccc730a 100644
--- a/tools/grit/grit/format/policy_templates/writers/template_writer.py
+++ b/tools/grit/grit/format/policy_templates/writers/template_writer.py
@@ -8,10 +8,11 @@ class TemplateWriter(object):
   The methods of this class will be called by PolicyTemplateGenerator.
   '''
 
-  def __init__(self, config, messages):
+  def __init__(self, platforms, config, messages):
     '''Initializes a TemplateWriter object.
 
     Args:
+      platforms: List of platforms for which this writer can write policies.
       config: A dictionary of information required to generate the template.
         It contains some key-value pairs, including the following examples:
           'build': 'chrome' or 'chromium'
@@ -25,6 +26,7 @@ class TemplateWriter(object):
         IDS_POLICY_WIN_SUPPORTED_WINXPSP2 message in ADM files, because that
         cannot be associated with any policy or group.
     '''
+    self.platforms = platforms
     self.config = config
     self.messages = messages
 
@@ -78,3 +80,17 @@ class TemplateWriter(object):
       The generated template from the the internal buffer as a string.
     '''
     raise NotImplementedError()
+
+  def IsPolicySupported(self, policy):
+    '''Checks if the writer is interested in writing a given policy.
+
+    Args:
+      policy: The dictionary of the policy.
+
+    Returns:
+      True if the writer chooses to include 'policy' in its output.
+    '''
+    for platform in self.platforms:
+      if platform in policy['annotations']['platforms']:
+        return True
+    return False