policy docs: Remove confusing reference to ShowModalDialog.

components/policy/resources/policy_templates.json

 {
 # policy_templates.json - Metafile for policy templates
 #
 # The content of this file is evaluated as a Python expression.
 #
 # This file is used as input to generate the following policy templates:
 # ADM, ADMX+ADML, MCX/plist and html documentation.
 #
 # Policy templates are user interface definitions or documents about the
 # policies that can be used to configure Chrome. Each policy is a name-value
@@ skipping 7661 matching lines @@
       If the policy is left not set, the user can choose an image to be shown on the desktop and on the login screen background.''',
     },
     {
       'name': 'EnableDeprecatedWebPlatformFeatures',
       'type': 'string-enum-list',
       'schema': {
         'type': 'array',
         'items': {
           'type': 'string',
           'enum': [
-            'ShowModalDialog_EffectiveUntil20150430'
+            'ExampleDeprecatedFeature_EffectiveUntil20080902'
           ],
         },
       },
       'items': [
         {
-          'name': 'ShowModalDialog',
-          'value': 'ShowModalDialog_EffectiveUntil20150430',
-          'caption': '''Enable ShowModalDialog API through 2015.04.30''',
+          'name': 'ExampleDeprecatedFeature',
+          'value': 'ExampleDeprecatedFeature_EffectiveUntil20080902',
+          'caption': '''Enable ExampleDeprecatedFeature API through 2008/09/02''',
         }
       ],
       'supported_on': ['chrome.*:37-', 'chrome_os:37-', 'android:37-'],
       'features': {
         'dynamic_refresh': True,
         'per_profile': True,
       },
-      'example_value': ['ShowModalDialog_EffectiveUntil20150430'],
+      'example_value': ['ExampleDeprecatedFeature_EffectiveUntil20080902'],
       'id': 270,
       'caption': '''Enable deprecated web platform features for a limited time''',
       'tags': ['system-security'],
       'desc': '''Specify a list of deprecated web platform features to re-enable temporarily.
 
       This policy gives administrators the ability to re-enable deprecated web platform features for a limited time. Features are identified by a string tag and the features corresponding to the tags included in the list specified by this policy will get re-enabled.
 
       If this policy is left not set, or the list is empty or does not match one of the supported string tags, all deprecated web platform features will remain disabled.
 
       While the policy itself is supported on the above platforms, the feature it is enabling may be available on fewer platforms. Not all deprecated Web Platform features can be re-enabled. Only the ones explicitly listed below can be for a limited period of time, which is different per feature. The general format of the string tag will be [DeprecatedFeatureName]_EffectiveUntil[yyyymmdd]. As reference, you can find the intent behind the Web Platform feature changes at https://bit.ly/blinkintents.
@@ skipping 893 matching lines @@
       'desc': '''Text appended in parentheses next to the policies top-level container to indicate that those policies are of the Recommended level''',
       'text': 'Default Settings (users can override)',
     },
     'doc_complex_policies_on_windows': {
       'desc': '''Text pointing the user to a help article for complex policies on Windows''',
       'text': '''encoded as a JSON string, for details see <ph name="COMPLEX_POLICIES_URL">https://www.chromium.org/administrators/complex-policies-on-windows<ex>https://www.chromium.org/administrators/complex-policies-on-windows</ex></ph>''',
     },
   },
   'placeholders': [],
 }