Revert "Adding supported checks for getCssCanvasContext."

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 463656f6b90ec8d6b9581cf3ddc69a50e4b705ef..e1bb5bab60a294ce6f10e65e093e1be0876ad862 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -12218,39 +12218,7 @@ class HtmlDocument extends Document {
     return document.$dom_elementFromPoint(x, y);
   }
 
-  /**
-   * Checks if the getCssCanvasContext API is supported on the current platform.
-   *
-   * See also:
-   *
-   * * [getCssCanvasContext]
-   */
-  static bool get supportsState => true;
-
-
-  /**
-   * Gets a CanvasRenderingContext which can be used as the CSS background of an
-   * element.
-   *
-   * CSS:
-   *
-   *     background: -webkit-canvas(backgroundCanvas)
-   *
-   * Generate the canvas:
-   *
-   *     var context = document.getCssCanvasContext('2d', 'backgroundCanvas',
-   *         100, 100);
-   *     context.fillStyle = 'red';
-   *     context.fillRect(0, 0, 100, 100);
-   *
-   * See also:
-   *
-   * * [supportsCssCanvasContext]
-   * * [CanvasElement.getContext]
-   */
-  @SupportedBrowser(SupportedBrowser.CHROME)
-  @SupportedBrowser(SupportedBrowser.SAFARI)
-  @Experimental()
+  /** @domName Document.getCSSCanvasContext */
   CanvasRenderingContext getCssCanvasContext(String contextId, String name,
       int width, int height) {
     return document.$dom_getCssCanvasContext(contextId, name, width, height);