Updating IDL files from Chrome roll.

sdk/lib/web_gl/dart2js/web_gl_dart2js.dart

 /**
  * 3D programming in the browser.
  */
 library dart.dom.web_gl;
 
 import 'dart:collection';
 import 'dart:_internal' hide deprecated;
 import 'dart:html';
 import 'dart:html_common';
 import 'dart:_native_typed_data';
@@ skipping 503 matching lines @@
   bool alpha;
 
   @DomName('WebGLContextAttributes.antialias')
   @DocsEditable()
   bool antialias;
 
   @DomName('WebGLContextAttributes.depth')
   @DocsEditable()
   bool depth;
 
+  @DomName('WebGLContextAttributes.failIfMajorPerformanceCaveat')
+  @DocsEditable()
+  @Experimental() // untriaged
+  bool failIfMajorPerformanceCaveat;
+
   @DomName('WebGLContextAttributes.premultipliedAlpha')
   @DocsEditable()
   bool premultipliedAlpha;
 
   @DomName('WebGLContextAttributes.preserveDrawingBuffer')
   @DocsEditable()
   bool preserveDrawingBuffer;
 
   @DomName('WebGLContextAttributes.stencil')
   @DocsEditable()
@@ skipping 2696 matching lines @@
 
 
 @DocsEditable()
 @DomName('WebGLVertexArrayObjectOES')
 // http://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
 @Experimental() // experimental
 class VertexArrayObject extends Interceptor native "WebGLVertexArrayObjectOES" {
   // To suppress missing implicit constructor warnings.
   factory VertexArrayObject._() { throw new UnsupportedError("Not supported"); }
 }