Add new extension APIs related to animation policy.

chrome/common/extensions/api/accessibility_features.json

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [
   {
     "namespace": "accessibilityFeatures",
-    "platforms": ["chromeos"],
     "description": "Use the <code>chrome.accessibilityFeatures</code> API to manage Chrome's accessibility features. This API relies on the <a href='types#ChromeSetting'>ChromeSetting prototype of the type API</a> for getting and setting individual accessibility features. In order to get feature states the extension must request <code>accessibilityFeatures.read</code> permission. For modifying feature state, the extension needs <code>accessibilityFeatures.modify</code> permission. Note that <code>accessibilityFeatures.modify</code> does not imply <code>accessibilityFeatures.read</code> permission.",
     "properties": {
       "spokenFeedback": {
         "$ref": "types.ChromeSetting",
         "description": "Spoken feedback (text-to-speech). The value indicates whether the feature is enabled or not. <code>get()</code> requires <code>accessibilityFeatures.read</code> permission. <code>set()</code> and <code>clear()</code> require <code>accessibilityFeatures.modify</code> permission.",
         "value": ["spokenFeedback", {"type": "boolean"}]
       },
       "largeCursor": {
         "$ref": "types.ChromeSetting",
         "description": "Enlarged cursor. The value indicates whether the feature is enabled or not. <code>get()</code> requires <code>accessibilityFeatures.read</code> permission. <code>set()</code> and <code>clear()</code> require <code>accessibilityFeatures.modify</code> permission.",
@@ skipping 16 matching lines @@
       },
       "autoclick": {
         "$ref": "types.ChromeSetting",
         "description":"Auto mouse click after mouse stops moving. The value indicates whether the feature is enabled or not. <code>get()</code> requires <code>accessibilityFeatures.read</code> permission. <code>set()</code> and <code>clear()</code> require <code>accessibilityFeatures.modify</code> permission.",
         "value": ["autoclick", {"type": "boolean"}]
       },
       "virtualKeyboard": {
         "$ref": "types.ChromeSetting",
         "description": "Virtual on-screen keyboard. The value indicates whether the feature is enabled or not. <code>get()</code> requires <code>accessibilityFeatures.read</code> permission. <code>set()</code> and <code>clear()</code> require <code>accessibilityFeatures.modify</code> permission.",
         "value": ["virtualKeyboard", {"type": "boolean"}]
+      },
+      "animationPolicy": {
+        "$ref": "types.ChromeSetting",
+        "description": "Policy for animated images. The value indicates how to handle animated images on web pages. The value indicates policy, one of allowd, once and none. <code>get()</code> requires <code>accessibilityFeatures.read</code> permission. <code>set()</code> and <code>clear()</code> require <code>accessibilityFeatures.modify</code> permission.",

[not at google - send to devlin, 2014/12/11 17:48:15]

The enum is self-documenting, so you don't need to spell out here "The value
indicates policy, one of allowd, once and none" etc, just leave out that
sentence.

[je_julie(Not used), 2014/12/12 13:15:45]

Done

+        "value": ["animationPolicy", {"type": "string", "enum": ["allowed", "once", "none"]}]

[not at google - send to devlin, 2014/12/11 17:48:15]

... but the enum is even better if you can document it. Note that I'm doing some
wrapping here, and you should too, otherwise it will be an awfully long line. It
will look like this:

"value": [
  "animationPolicy", {
    "type": "string",
    "enum": [{
      "value": "allowed".
      "description": "Images are allowed to animate."
    }, {
      "value": "once",
      "description": "...",
    }, {
      "value": "none",
      "description": "..."
    }]
  }
],

Also note that I think "never" might be a better word that "none" but I'll let
dmazzoni@ comment on that.

[je_julie(Not used), 2014/12/12 13:15:45]

I updated it.

       }
     }
   }
 ]