Deprecate chrome.extension.sendRequest in favor of sendMessage, with a safer

chrome/common/extensions/api/extension.json

 // Copyright (c) 2012 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": "extension",
     "nocompile": true,
     "dependencies": [ "tabs" ],
     "types": [
@@ skipping 73 matching lines @@
         "returns": {
           "$ref": "Port",
           "description": "Port through which messages can be sent and received with the extension. The port's <a href='extension.html#type-Port'>onDisconnect</a> event is fired if extension does not exist. "
         }
       },
       {
         "name": "sendRequest",
         "type": "function",
         "allowAmbiguousOptionalArguments": true,
         "unprivileged": true,
-        "description": "Sends a single request to other listeners within the extension. Similar to chrome.extension.connect, but only sends a single request with an optional response. The <a href='extension.html#event-onRequest'>chrome.extension.onRequest</a> event is fired in each page of the extension.",
+        "description": "Deprecated: Please use sendMessage.",
         "parameters": [
           {"type": "string", "name": "extensionId", "optional": true, "description": "The extension ID of the extension you want to connect to. If omitted, default is your own extension."},
           { "type": "any", "name": "request" },
           {
             "type": "function",
             "name": "responseCallback",
             "optional": true,
             "parameters": [
               {
                 "name": "response",
                 "type": "any",
                 "description": "The JSON response object sent by the handler of the request. If an error occurs while connecting to the extension, the callback will be called with no arguments and <a href='extension.html#property-lastError'>chrome.extension.lastError</a> will be set to the error message."
               }
             ]
           }
         ]
       },
       {
+        "name": "sendMessage",
+        "type": "function",
+        "allowAmbiguousOptionalArguments": true,
+        "unprivileged": true,
+        "description": "Sends a single message to other listeners within the extension. Similar to chrome.extension.connect, but only sends a single message with an optional response. The <a href='extension.html#event-onMessage'>chrome.extension.onMessage</a> event is fired in each page of the extension.",
+        "parameters": [
+          {"type": "string", "name": "extensionId", "optional": true, "description": "The extension ID of the extension you want to connect to. If omitted, default is your own extension."},
+          { "type": "any", "name": "message" },
+          {
+            "type": "function",
+            "name": "responseCallback",
+            "optional": true,
+            "parameters": [
+              {
+                "name": "response",
+                "type": "any",
+                "description": "The JSON response object sent by the handler of the message. If an error occurs while connecting to the extension, the callback will be called with no arguments and <a href='extension.html#property-lastError'>chrome.extension.lastError</a> will be set to the error message."
+              }
+            ]
+          }
+        ]
+      },
+      {
         "name": "getURL",
         "type": "function",
         "unprivileged": true,
         "description": "Converts a relative path within an extension install directory to a fully-qualified URL.",
         "parameters": [
           {
             "type": "string",
             "name": "path",
             "description": "A path to a resource within an extension expressed relative to its install directory."
           }
@@ skipping 122 matching lines @@
         "description": "Fired when a connection is made from another extension.",
         "parameters": [
           {"$ref": "Port", "name": "port"}
         ]
       },
       {
         "name": "onRequest",
         "type": "function",
         "anonymous": true,
         "unprivileged": true,
-        "description": "Fired when a request is sent from either an extension process or a content script.",
+        "description": "Deprecated: please use onMessage.",
         "parameters": [
           {"name": "request", "type": "any", "description": "The request sent by the calling script."},
           {"name": "sender", "$ref": "MessageSender" },
           {"name": "sendResponse", "type": "function", "description": "Function to call (at most once) when you have a response. The argument should be any JSON-ifiable object, or undefined if there is no response. If you have more than one <code>onRequest</code> listener in the same document, then only one may send a response." }
         ]
       },
       {
         "name": "onRequestExternal",
         "type": "function",
         "anonymous": true,
-        "description": "Fired when a request is sent from another extension.",
+        "description": "Deprecated: please use onMessageExternal.",
         "parameters": [
           {"name": "request", "type": "any", "description": "The request sent by the calling script."},
           {"name": "sender", "$ref": "MessageSender" },
           {"name": "sendResponse", "type": "function", "description": "Function to call when you have a response. The argument should be any JSON-ifiable object, or undefined if there is no response." }
         ]
+      },
+      {
+        "name": "onMessage",
+        "type": "function",
+        "anonymous": true,
+        "unprivileged": true,
+        "description": "Fired when a message is sent from either an extension process or a content script.",
+        "parameters": [
+          {
+            "name": "details",
+            "type": "object",
+            "properties": {
+              "message": { "type": "any", "description": "The message sent by the calling script."},
+              "sender": { "$ref": "MessageSender" },
+              "sendResponse": { "type": "function", "description": "Function to call (at most once) when you have a response. The argument should be any JSON-ifiable object, or undefined if there is no response. If you have more than one <code>onMessage</code> listener in the same document, then only one may send a response. Note: accessing this property will keep the port open until you call the function, so don't access it unless you plan on calling it." }
+            }
+          }
+        ]
+      },
+      {
+        "name": "onMessageExternal",
+        "type": "function",
+        "anonymous": true,
+        "description": "Fired when a message is sent from another extension.",
+        "parameters": [
+          {
+            "name": "details",
+            "type": "object",
+            "properties": {
+              "message": { "type": "any", "description": "The message sent by the calling script."},
+              "sender": { "$ref": "MessageSender" },
+              "sendResponse": { "type": "function", "description": "Function to call (at most once) when you have a response. The argument should be any JSON-ifiable object, or undefined if there is no response. If you have more than one <code>onMessage</code> listener in the same document, then only one may send a response. Note: accessing this property will keep the port open until you call the function, so don't access it unless you plan on calling it." }
+            }
+          }
+        ]
       }
     ]
   }
 ]