Add support for authorization of HTTP client requests

runtime/bin/http.dart

Index: runtime/bin/http.dart
diff --git a/runtime/bin/http.dart b/runtime/bin/http.dart
index a3f4931c8dc36a568bc6b6d79fcbfa770e163ff4..959c30c608a212e3a28a771d182af13e67dd3968 100644
--- a/runtime/bin/http.dart
+++ b/runtime/bin/http.dart
@@ -364,8 +364,9 @@ abstract class HeaderValue {
    * Creates a new header value object from parsing a header value
    * string with both value and optional parameters.
    */
-  factory HeaderValue.fromString(String value) {
-    return new _HeaderValue.fromString(value);
+  factory HeaderValue.fromString(String value,
+                                 [String parameterSeparator = ";"]) {
+    return new _HeaderValue.fromString(value, parameterSeparator);
   }
 
   /**
@@ -709,6 +710,25 @@ abstract class HttpClient {
   HttpClientConnection postUrl(Uri url);
 
   /**
+   * Sets the function to be called when a site is requesting
+   * authentication. The URL requested and the security realm from the
+   * server are passed in the arguments [url] and [realm].
+   *
+   * If credentials exists the function should add these using
+   * [addCredentials] before returning.
+   *
+   * If the function returns true the request will be retried using
+   * the updated credentials. Otherwise response processing will
+   * continue normally.
+   */
+  set authenticate(bool f(Uri url, String scheme, String realm));
+
+  /**
+   * Add credentials to be used for authorizing HTTP requests.
+   */
+  void addCredentials(Uri url, String realm, HttpClientCredentials credentials);
+
+  /**
    * Sets the function used to resolve the proxy server to be used for
    * opening a HTTP connection to the specified [url]. If this
    * function is not set, direct connections will always be used.
@@ -904,6 +924,28 @@ abstract class HttpClientResponse {
   InputStream get inputStream;
 }
 
+
+abstract class HttpClientCredentials { }
+
+
+/**
+ * Represent credentials for basic authentication.
+ */
+abstract class HttpClientBasicCredentials extends HttpClientCredentials {
+  factory HttpClientBasicCredentials(String username, String password) =>
+      new _HttpClientBasicCredentials(username, password);
+}
+
+
+/**
+ * Represent credentials for digest authentication.
+ */
+abstract class HttpClientDigestCredentials extends HttpClientCredentials {
+  factory HttpClientDigestCredentials(String username, String password) =>
+      new _HttpClientDigestCredentials(username, password);
+}
+
+
 /**
  * Connection information.
  */