Additions to HttpRequest docs

tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate

Index: tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate b/tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate
index a19ba4d79dfb8e24f7a66cda13319a3bf814ea3f..539e645ac913da012101119d036c7d38e6a7c542 100644
--- a/tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate
+++ b/tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate
@@ -62,6 +62,17 @@ $(ANNOTATIONS)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
    * This is similar to [request] but specialized for HTTP GET requests which
    * return text content.
    *
+   * To add query parameters, append them to the [url] following a `?`,
+   * joining each key to its value with `=` and separating key-value pairs with
+   * `&`.
+   *
+   *     var name = Uri.encodeQueryComponent('John');
+   *     var id = Uri.encodeQueryComponent('42');
+   *     HttpRequest.getString('users.json?name=$name&id=$id')
+   *       .then((HttpRequest resp) {
+   *         // Do something with the response.
+   *     });
+   *
    * See also:
    *
    * * [request]
@@ -79,6 +90,20 @@ $(ANNOTATIONS)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
    * to sending a FormData object with broader browser support but limited to
    * String values.
    *
+   * If [data] is supplied, the key/value pairs are URI encoded with
+   * [Uri.encodeQueryComponent] and converted into an HTTP query string.
+   *
+   * Unless otherwise specified, this method appends the following header:
+   *
+   *     Content-Type: application/x-www-form-urlencoded; charset=UTF-8
+   *
+   * Here's an example of using this method:
+   *
+   *     var data = { 'firstName' : 'John', 'lastName' : 'Doe' };
+   *     HttpRequest.postFormData('/send', data).then((HttpRequest resp) {
+   *       // Do something with the response.
+   *     });
+   *
    * See also:
    *
    * * [request]
@@ -130,6 +155,24 @@ $(ANNOTATIONS)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
    * * The `Access-Control-Allow-Credentials` header of `url` must be set to true.
    * * If `Access-Control-Expose-Headers` has not been set to true, only a subset of all the response headers will be returned when calling [getAllRequestHeaders].
    *
+   * The following is equivalent to the [getString] sample above:
+   *
+   *     var name = Uri.encodeQueryComponent('John');
+   *     var id = Uri.encodeQueryComponent('42');
+   *     HttpRequest.request('users.json?name=$name&id=$id')
+   *       .then((HttpRequest resp) {
+   *         // Do something with the response.
+   *     });
+   *
+   * Here's an example of submitting an entire form with [FormData].
+   *
+   *     var myForm = querySelector('form#myForm');
+   *     var data = new FormData(myForm);
+   *     HttpRequest.request('/submit', method: 'POST', sendData: data)
+   *       .then((HttpRequest resp) {
+   *         // Do something with the response.
+   *     });
+   *
    * Note that requests for file:// URIs are only supported by Chrome extensions
    * with appropriate permissions in their manifest. Requests to file:// URIs
    * will also never fail- the Future will always complete successfully, even