[Extensions API] Remove inline enums

extensions/common/api/extension_types.json

Index: extensions/common/api/extension_types.json
diff --git a/extensions/common/api/extension_types.json b/extensions/common/api/extension_types.json
index 3efc2f23ae3e455cd3b5a724a85b7d0c794f95d9..29562ee0ed3509a7aa5e0b45b043cd8a4a1a18f3 100644
--- a/extensions/common/api/extension_types.json
+++ b/extensions/common/api/extension_types.json
@@ -8,14 +8,19 @@
     "description": "The <code>chrome.extensionTypes</code> API contains type declarations for Chrome extensions.",
     "types": [
       {
+        "id": "ImageFormat",
+        "type": "string",
+        "enum": ["jpeg", "png"],
+        "description": "The format of an image."
+      },
+      {
         "id": "ImageDetails",
         "type": "object",
         "description": "Details about the format and quality of an image.",
         "properties": {
           "format": {
-            "type": "string",
+            "$ref": "ImageFormat",
             "optional": true,
-            "enum": ["jpeg", "png"],
             "description": "The format of the resulting image.  Default is <code>\"jpeg\"</code>."
           },
           "quality": {
@@ -28,6 +33,12 @@
         }
       },
       {
+        "id": "RunAt",
+        "type": "string",
+        "enum": ["document_start", "document_end", "document_idle"],
+        "description": "The soonest that the JavaScript or CSS will be injected into the tab."
+      },
+      {
         "id": "InjectDetails",
         "type": "object",
         "description": "Details of the script or CSS to inject. Either the code or the file property must be set, but both may not be set at the same time.",
@@ -37,9 +48,8 @@
           "allFrames": {"type": "boolean", "optional": true, "description": "If allFrames is <code>true</code>, implies that the JavaScript or CSS should be injected into all frames of current page. By default, it's <code>false</code> and is only injected into the top frame."},
           "matchAboutBlank": {"type": "boolean", "optional": true, "description": "If matchAboutBlank is true, then the code is also injected in about:blank and about:srcdoc frames if your extension has access to its parent document. Code cannot be inserted in top-level about:-frames. By default it is <code>false</code>."},
           "runAt": {
-            "type": "string",
+            "$ref": "RunAt",
             "optional": true,
-            "enum": ["document_start", "document_end", "document_idle"],
             "description": "The soonest that the JavaScript or CSS will be injected into the tab. Defaults to \"document_idle\"."
           }
         }