Handle extension webrequest API on the IO thread. This speeds up blocking event

chrome/renderer/resources/extension_process_bindings.js

 // Copyright (c) 2011 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.
 
 // This script contains privileged chrome extension related javascript APIs.
 // It is loaded by pages whose URL has the chrome-extension protocol.
 
 var chrome = chrome || {};
 (function() {
   native function GetExtensionAPIDefinition();
@@ skipping 165 matching lines @@
 
     request.args = [];
     for (var k = 0; k < argCount; k++) {
       request.args[k] = args[k];
     }
 
     return request;
   }
 
   // Send an API request and optionally register a callback.
-  function sendRequest(functionName, args, argSchemas, customCallback) {
+  // |opt_args| is an object with optional parameters as follows:
+  // - noStringify: true if we should not stringify the request arguments.
+  // - customCallback: a callback that should be called instead of the standard
+  //   callback.
+  // - nativeFunction: the v8 native function to handle the request, or
+  //   StartRequest if missing.
+  // - forIOThread: true if this function should be handled on the browser IO
+  //   thread.
+  function sendRequest(functionName, args, argSchemas, opt_args) {
+    if (!opt_args)
+      opt_args = {};
     var request = prepareRequest(args, argSchemas);
-    if (customCallback) {
-      request.customCallback = customCallback;
+    if (opt_args.customCallback) {
+      request.customCallback = opt_args.customCallback;
     }
     // JSON.stringify doesn't support a root object which is undefined.
     if (request.args === undefined)
       request.args = null;
 
-    var sargs = chromeHidden.JSON.stringify(request.args);
+    var sargs = opt_args.noStringify ?
+        request.args : chromeHidden.JSON.stringify(request.args);
+    var nativeFunction = opt_args.nativeFunction || StartRequest;
 
     var requestId = GetNextRequestId();
     requests[requestId] = request;
-    var hasCallback = (request.callback || customCallback) ? true : false;
-    return StartRequest(functionName, sargs, requestId, hasCallback);
-  }
-
-  // Send a special API request that is not JSON stringifiable, and optionally
-  // register a callback.
-  function sendCustomRequest(nativeFunction, functionName, args, argSchemas) {
-    var request = prepareRequest(args, argSchemas);
-    var requestId = GetNextRequestId();
-    requests[requestId] = request;
-    return nativeFunction(functionName, request.args, requestId,
-                          request.callback ? true : false);
+    var hasCallback =
+        (request.callback || opt_args.customCallback) ? true : false;
+    return nativeFunction(functionName, sargs, requestId, hasCallback,
+                          opt_args.forIOThread);
   }
 
   // Helper function for positioning pop-up windows relative to DOM objects.
   // Returns the absolute position of the given element relative to the hosting
   // browser frame.
   function findAbsolutePosition(domElement) {
     var left = domElement.offsetLeft;
     var top = domElement.offsetTop;
 
     // Ascend through the parent hierarchy, taking into account object nesting
@@ skipping 397 matching lines @@
             chromeHidden.validate(args, this.definition.parameters);
             if (this.updateArgumentsPostValidate)
               args = this.updateArgumentsPostValidate.apply(this, args);
 
             var retval;
             if (this.handleRequest) {
               retval = this.handleRequest.apply(this, args);
             } else {
               retval = sendRequest(this.name, args,
                                    this.definition.parameters,
-                                   this.customCallback);
+                                   {customCallback: this.customCallback});
             }
 
             // Validate return value if defined - only in debug.
             if (chromeHidden.validateCallbacks &&
                 chromeHidden.validate &&
                 this.definition.returns) {
               chromeHidden.validate([retval], [this.definition.returns]);
             }
             return retval;
           }).bind(apiFunction);
@@ skipping 170 matching lines @@
               "The imageData property must contain an ImageData object.");
         }
 
         if (details.imageData.width > iconSize ||
             details.imageData.height > iconSize) {
           throw new Error(
               "The imageData property must contain an ImageData object that " +
               "is no larger than " + iconSize + " pixels square.");
         }
 
-        sendCustomRequest(nativeFunction, name, [details], parameters);
+        sendRequest(name, [details], parameters,
+                    {noStringify: true, nativeFunction: nativeFunction});
       } else if ("path" in details) {
         var img = new Image();
         img.onerror = function() {
           console.error("Could not load " + actionType + " icon '" +
                         details.path + "'.");
         };
         img.onload = function() {
           var canvas = document.createElement("canvas");
           canvas.width = img.width > iconSize ? iconSize : img.width;
           canvas.height = img.height > iconSize ? iconSize : img.height;
 
           var canvas_context = canvas.getContext('2d');
           canvas_context.clearRect(0, 0, canvas.width, canvas.height);
           canvas_context.drawImage(img, 0, 0, canvas.width, canvas.height);
           delete details.path;
           details.imageData = canvas_context.getImageData(0, 0, canvas.width,
                                                           canvas.height);
-          sendCustomRequest(nativeFunction, name, [details], parameters);
+          sendRequest(name, [details], parameters,
+                      {noStringify: true, nativeFunction: nativeFunction});
         };
         img.src = details.path;
       } else {
         throw new Error(
             "Either the path or imageData property must be specified.");
       }
     }
 
     function setExtensionActionIconCommon(details, name, parameters,
                                           actionType) {
@@ skipping 19 matching lines @@
           details, this.name, this.definition.parameters, "sidebar",
           SIDEBAR_ICON_SIZE, SetIconCommon);
     };
 
     apiFunctions["contextMenus.create"].handleRequest =
         function() {
       var args = arguments;
       var id = GetNextContextMenuId();
       args[0].generatedId = id;
       sendRequest(this.name, args, this.definition.parameters,
-                  this.customCallback);
+                  {customCallback: this.customCallback});
       return id;
     };
 
     apiFunctions["omnibox.setDefaultSuggestion"].handleRequest =
         function(details) {
       var parseResult = parseOmniboxDescription(details.description);
       sendRequest(this.name, [parseResult], this.definition.parameters);
     };
 
+    apiFunctions["experimental.webRequest.addEventListener"].handleRequest =
+        function() {
+      var args = Array.prototype.slice.call(arguments);
+      sendRequest(this.name, args, this.definition.parameters,
+                  {forIOThread: true});
+    };
+
+    apiFunctions["experimental.webRequest.eventHandled"].handleRequest =
+        function() {
+      var args = Array.prototype.slice.call(arguments);
+      sendRequest(this.name, args, this.definition.parameters,
+                  {forIOThread: true});
+    };
+
     apiFunctions["contextMenus.create"].customCallback =
         function(name, request, response) {
       if (chrome.extension.lastError) {
         return;
       }
 
       var id = request.args[0].generatedId;
 
       // Set up the onclick handler if we were passed one in the request.
       var onclick = request.args.length ? request.args[0].onclick : null;
@@ skipping 76 matching lines @@
 
   if (!chrome.experimental)
     chrome.experimental = {};
 
   if (!chrome.experimental.accessibility)
     chrome.experimental.accessibility = {};
 
   if (!chrome.experimental.tts)
     chrome.experimental.tts = {};
 })();