Adding supported checks and flags to FormData

sdk/lib/html/dartium/html_dartium.dart

Index: sdk/lib/html/dartium/html_dartium.dart
diff --git a/sdk/lib/html/dartium/html_dartium.dart b/sdk/lib/html/dartium/html_dartium.dart
index b9de515c68fe68ef3c44062308682311f9a21d6a..6f5653ae627e482854ea52114102e81e078ab98b 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -12357,6 +12357,10 @@ class Float64Array extends ArrayBufferView implements List<num> {
 
 @DocsEditable
 @DomName('FormData')
+@SupportedBrowser(SupportedBrowser.CHROME)
+@SupportedBrowser(SupportedBrowser.FIREFOX)
+@SupportedBrowser(SupportedBrowser.IE, '10')
+@SupportedBrowser(SupportedBrowser.SAFARI)
 class FormData extends NativeFieldWrapperClass1 {
   FormData.internal();
   factory FormData([FormElement form]) => _create(form);
@@ -12364,6 +12368,9 @@ class FormData extends NativeFieldWrapperClass1 {
   @DocsEditable
   static FormData _create(form) native "DOMFormData_constructorCallback";
 
+  /// Checks if this type is supported on the current platform.
+  static bool get supported => true;
+
   @DomName('DOMFormData.append')
   @DocsEditable
   void append(String name, value, [String filename]) native "DOMFormData_append_Callback";
@@ -13569,6 +13576,10 @@ class HttpRequest extends EventTarget {
    */
   @DomName('XMLHttpRequest.response')
   @DocsEditable
+  @SupportedBrowser(SupportedBrowser.CHROME)
+  @SupportedBrowser(SupportedBrowser.FIREFOX)
+  @SupportedBrowser(SupportedBrowser.IE, '10')
+  @SupportedBrowser(SupportedBrowser.SAFARI)
   Object get response native "XMLHttpRequest_response_Getter";
 
   /**
@@ -13778,6 +13789,10 @@ class HttpRequest extends EventTarget {
    */
   @DomName('XMLHttpRequest.onloadend')
   @DocsEditable
+  @SupportedBrowser(SupportedBrowser.CHROME)
+  @SupportedBrowser(SupportedBrowser.FIREFOX)
+  @SupportedBrowser(SupportedBrowser.IE, '10')
+  @SupportedBrowser(SupportedBrowser.SAFARI)
   Stream<ProgressEvent> get onLoadEnd => loadEndEvent.forTarget(this);
 
   /**
@@ -13797,6 +13812,10 @@ class HttpRequest extends EventTarget {
    */
   @DomName('XMLHttpRequest.onprogress')
   @DocsEditable
+  @SupportedBrowser(SupportedBrowser.CHROME)
+  @SupportedBrowser(SupportedBrowser.FIREFOX)
+  @SupportedBrowser(SupportedBrowser.IE, '10')
+  @SupportedBrowser(SupportedBrowser.SAFARI)
   Stream<ProgressEvent> get onProgress => progressEvent.forTarget(this);
 
   /**