Use primary/secondary for URLs and patterns everywhere in the content settings extension API.

chrome/common/extensions/api/extension_api.json

 [
   {
     "namespace": "extension",
     "unprivileged": true,
     "types": [
       {
         "id": "MessageSender",
         "type": "object",
         "description": "An object containing information about the script context that sent a message or request.",
         "properties": {
@@ skipping 5844 matching lines @@
           },
           {
             "name": "get",
             "type": "function",
             "description": "Get the current content setting for a given pair of URLs.",
             "parameters": [
               {
                 "name": "details",
                 "type": "object",
                 "properties": {
-                  "embeddedUrl": {
+                  "primaryUrl": {
                     "type": "string",
-                    "description": "The URL of the frame or object for which the content settings should be retrieved."
+                    "description": "The primary URL for which the content setting should be retrieved. Note that the meaning of a primary URL depends on the content type."
                   },
-                  "topLevelUrl": {
+                  "secondaryUrl": {
                     "type": "string",
-                    "description": "The URL of the top-level frame."
+                    "description": "The secondary URL for which the content setting should be retrieved. Defaults to the primary URL. Note that the meaning of a secondary URL depends on the content type, and not all content types use secondary URLs.",
+                    "optional": true
                   },
                   "resourceIdentifier": {
                     "$ref": "ResourceIdentifier",
                     "optional": true,
                     "description": "A more specific identifier of the type of content for which the settings should be retrieved."
                   },
                   "incognito": {
                     "type": "boolean",
                     "optional": true,
                     "description": "Whether to check the content settings for an incognito session. (default false)"
@@ skipping 20 matching lines @@
           },
           {
             "name": "set",
             "type": "function",
             "description": "Apply a new content setting rule.",
             "parameters": [
               {
                 "name": "details",
                 "type": "object",
                 "properties": {
-                  "topLevelPattern": {
+                  "primaryPattern": {
                     "type": "string",
-                    "description": "The pattern for the top-level frame URL. For details on the format of a pattern, see <a href='match_patterns.html'>Match Patterns</a>."
+                    "description": "The pattern for the primary URL. For details on the format of a pattern, see <a href='match_patterns.html'>Match Patterns</a>."
                   },
-                  "embeddedPattern": {
+                  "secondaryPattern": {
                     "type": "string",
-                    "description": "The pattern for the frame or object URL. For details on the format of a pattern, see <a href='match_patterns.html'>Match Patterns</a>."
+                    "description": "The pattern for the secondary URL. Defaults to matching all URLs. For details on the format of a pattern, see <a href='match_patterns.html'>Match Patterns</a>.",
+                    "optional": true
                   },
                   "resourceIdentifier": {
                     "$ref": "ResourceIdentifier",
                     "optional": true,
                     "description": "The resource identifier for the content type."
                   },
                   "setting": {
                     "type": "any",
                     "description": "The setting applied by this rule. See the description of the individual ContentSetting objects for the possible values."
                   },
@@ skipping 54 matching lines @@
           },
           "hyperlinkAuditingEnabled": {
             "$ref": "ChromeSetting",
             "value": ["hyperlinkAuditingEnabled", {"type":"boolean"}],
             "description": "Whether to enable hyperlink auditing (\"&lt;a ping&gt;\"). The value of this preference is of type boolean, and the default value is true."
           }
         }
       },
       "cookies": {
         "$ref": "ContentSetting",
-        "description": "Whether to allow cookies and other local data to be set by websites. One of<br><var>allow</var>: Accept cookies,<br><var>block</var>: Block cookies,<br><var>session_only</var>: Accept cookies only for the current session. Default is <var>allow</var>.",
+        "description": "Whether to allow cookies and other local data to be set by websites. One of<br><var>allow</var>: Accept cookies,<br><var>block</var>: Block cookies,<br><var>session_only</var>: Accept cookies only for the current session. Default is <var>allow</var>.<br>The primary URL is the URL representing the cookie origin. The secondary URL is the URL of the top-level frame.",
         "value": [
           "cookies",
           {"type":"string", "enum": ["allow", "block", "session_only"]}
         ]
       },
       "images": {
         "$ref": "ContentSetting",
-        "description": "Whether to show images. One of<br><var>allow</var>: Show images,<br><var>block</var>: Don't show images. Default is <var>allow</var>.",
+        "description": "Whether to show images. One of<br><var>allow</var>: Show images,<br><var>block</var>: Don't show images. Default is <var>allow</var>.<br>The primary URL is the main-frame URL. The secondary URL is not used.",
         "value": [
           "images",
           {"type":"string", "enum": ["allow", "block"]}
         ]
       },
       "javascript": {
         "$ref": "ContentSetting",
-        "description": "Whether to run Javascript. One of<br><var>allow</var>: Run Javascript,<br><var>block</var>: Don't run Javascript. Default is <var>allow</var>.",
+        "description": "Whether to run Javascript. One of<br><var>allow</var>: Run Javascript,<br><var>block</var>: Don't run Javascript. Default is <var>allow</var>.<br>The primary URL is the main-frame URL. The secondary URL is not used.",
         "value": [
           "javascript",
           {"type":"string", "enum": ["allow", "block"]}
         ]
       },
       "plugins": {
         "$ref": "ContentSetting",
-        "description": "Whether to run plug-ins. One of<br><var>allow</var>: Run plug-ins automatically,<br><var>block</var>: Don't run plug-ins automatically. Default is <var>allow</var>.",
+        "description": "Whether to run plug-ins. One of<br><var>allow</var>: Run plug-ins automatically,<br><var>block</var>: Don't run plug-ins automatically. Default is <var>allow</var>.<br>The primary URL is the main-frame URL. The secondary URL is not used.",
         "value": [
           "plugins",
           {"type":"string", "enum": ["allow", "block"]}
         ]
       },
       "popups": {
         "$ref": "ContentSetting",
-        "description": "Whether to allow sites to show pop-ups. One of<br><var>allow</var>: Allow sites to show pop-ups,<br><var>block</var>: Don't allow sites to show pop-ups. Default is <var>block</var>.",
+        "description": "Whether to allow sites to show pop-ups. One of<br><var>allow</var>: Allow sites to show pop-ups,<br><var>block</var>: Don't allow sites to show pop-ups. Default is <var>block</var>.<br>The primary URL is the main-frame URL. The secondary URL is not used.",
         "value": [
           "popups",
           {"type":"string", "enum": ["allow", "block"]}
         ]
       },
       "notifications": {
         "$ref": "ContentSetting",
-        "description": "Whether to allow sites to show desktop notifications. One of<br><var>allow</var>: Allow sites to show desktop notifications,<br><var>block</var>: Don't allow sites to show desktop notifications,<br><var>ask</var>: Ask when a site wants to show desktop notifications. Default is <var>ask</var>.",
+        "description": "Whether to allow sites to show desktop notifications. One of<br><var>allow</var>: Allow sites to show desktop notifications,<br><var>block</var>: Don't allow sites to show desktop notifications,<br><var>ask</var>: Ask when a site wants to show desktop notifications. Default is <var>ask</var>.<br>The primary URL is the main-frame URL. The secondary URL is not used.",
         "value": [
           "notifications",
           {"type":"string", "enum": ["allow", "block", "ask"]}
         ]
       }
     }
   },
   {
     "namespace": "experimental.debugger",
     "functions": [
@@ skipping 216 matching lines @@
             "type": "function",
             "name": "callback",
             "optional": true,
             "description": "A callback when the function is complete. Any errors will be reported in <a href='extension.html#property-lastError'>chrome.extension.lastError</a>."
           }
         ]
       }
     ]
   }
 ]