Fix definition of clearComposition to match the rest of the API

chrome/common/extensions/api/extension_api.json

Index: chrome/common/extensions/api/extension_api.json
diff --git a/chrome/common/extensions/api/extension_api.json b/chrome/common/extensions/api/extension_api.json
index 51c54280ad771daf754a4f8b90e9dd11fa8ebf36..c7ca99fb5c34a0297cb25b89e8ec54d35b8affb5 100644
--- a/chrome/common/extensions/api/extension_api.json
+++ b/chrome/common/extensions/api/extension_api.json
@@ -3362,9 +3362,14 @@
         "description": "Clear the current composition. If this extension does not own the active IME, this fails.",
         "parameters": [
           {
-            "name": "contextID",
-            "description": "ID of the context with the composition text. This is the value provided in the InputContext from onFocus.",
-            "type": "integer"
+            "name": "parameters",
+            "type": "object",
+            "properties": {
+              "contextID": {
+                "description": "ID of the context where the composition will be cleared",
+                "type": "integer"
+              }
+            }
           },
           {
             "type": "function",