Pass pepper apps API calls through the existing js apps API bindings.

chrome/renderer/resources/extensions/pepper_request.js

+// Copyright 2013 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.
+
+var SendResponse = requireNative('pepper_request_natives').SendResponse;
+var GetAvailability = requireNative('v8_context').GetAvailability;
+var utils = require('utils');
+var schemaRegistry = requireNative('schema_registry');
+
+function takesCallback(targetName) {
+  var parts = $String.split(targetName, '.');
+  var schemaName = $Array.join($Array.slice(parts, 0, parts.length - 1), '.');
+  var functionName = parts[parts.length - 1];
+  var functions = schemaRegistry.GetSchema(schemaName).functions;
+  var parameters = utils.lookup(functions, "name", functionName).parameters;

[not at google - send to devlin, 2013/12/10 22:22:16]

here and below use ' not "

[Sam McNally, 2013/12/10 23:19:09]

Done.

+  return parameters.length > 0 &&
+         parameters[parameters.length - 1].type == "function";
+}
+
+function resolveName(name) {
+  var availability = GetAvailability(name);
+  if (!availability.is_available)
+    throw Error(availability.message);
+  var item = chrome;
+  var nameComponents = $String.split(name, '.');
+  for (var i = 0; i < nameComponents.length; i++) {
+    item = item[nameComponents[i]];
+  }
+  return item;
+}
+
+function startRequest(targetName, requestId) {
+  var args = $Array.slice(arguments, 2);
+  try {
+    var hasCallback = takesCallback(targetName);
+    if (hasCallback) {
+      args.push(function() {
+        var error = null;
+        if (chrome.runtime.lastError)
+          error = chrome.runtime.lastError.message;
+        SendResponse(requestId, $Array.slice(arguments), error);
+      });
+    }
+    var target = resolveName(targetName);
+    var result = $Function.apply(target, null, args);
+    if (!hasCallback)
+      SendResponse(requestId, [result], null);
+  } catch (e) {
+    // TODO(sammc): Catch this from C++.
+    return e.message;
+  }
+}
+
+exports.startRequest = startRequest;