[Sanitizer] Implement config and defaultConfig as attributes.

This follows spec discussion at github.com/WICG/sanitizer-api/issues/92

Bug: 1213893
Change-Id: I9b7102fecd7f896b5cec160592a5d6bd60c16716
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2996826
Commit-Queue: Daniel Vogelheim <vogelheim@chromium.org>
Reviewed-by: Yifan Luo <lyf@chromium.org>
Cr-Commit-Position: refs/heads/master@{#898870}

third_party/blink/renderer/modules/sanitizer_api/sanitizer.idl

@@ -16,6 +16,6 @@ typedef (DOMString or TrustedHTML or DocumentFragment or Document) SanitizerInpu
   [MeasureAs=SanitizerAPIToFragment, CallWith=ScriptState, RaisesException] DocumentFragment sanitize(SanitizerInputWithTrustedHTML input);
   [MeasureAs=SanitizerAPIToString, CallWith=ScriptState, RaisesException] DOMString sanitizeToString(SanitizerInput input);
 
-  [MeasureAs=SanitizerAPIGetConfig] SanitizerConfig config();
-  [MeasureAs=SanitizerAPIGetDefaultConfig] static SanitizerConfig defaultConfig();
+  [MeasureAs=SanitizerAPIGetConfig] readonly attribute SanitizerConfig config;
+  [MeasureAs=SanitizerAPIGetDefaultConfig] static readonly attribute SanitizerConfig defaultConfig;
 };

third_party/blink/web_tests/webexposed/global-interface-listing-expected.txt

@@ -8148,9 +8148,9 @@ interface SVGViewElement : SVGElement
     method constructor
     setter zoomAndPan
 interface Sanitizer
-    static method defaultConfig
+    static getter defaultConfig
     attribute @@toStringTag
-    method config
+    getter config
     method constructor
     method sanitize
     method sanitizeToString

third_party/blink/web_tests/wpt_internal/sanitizer-api/sanitizer-query-config.https.tenative.html

@@ -21,23 +21,23 @@
 
   test(t => {
     // Quick sanity test: Test a few default values.
-    assert_in_array("div", Sanitizer.defaultConfig().allowElements);
-    assert_false(Sanitizer.defaultConfig().allowElements.includes("script"));
-    assert_false(Sanitizer.defaultConfig().allowElements.includes("noscript"));
+    assert_in_array("div", Sanitizer.defaultConfig.allowElements);
+    assert_false(Sanitizer.defaultConfig.allowElements.includes("script"));
+    assert_false(Sanitizer.defaultConfig.allowElements.includes("noscript"));
 
-    assert_true("span" in Sanitizer.defaultConfig().allowAttributes);
-    assert_false("onclick" in Sanitizer.defaultConfig().allowAttributes);
+    assert_true("span" in Sanitizer.defaultConfig.allowAttributes);
+    assert_false("onclick" in Sanitizer.defaultConfig.allowAttributes);
 
-    assert_false("dropElements" in Sanitizer.defaultConfig());
-    assert_false("blockElements" in Sanitizer.defaultConfig());
-    assert_false("dropAttributes" in Sanitizer.defaultConfig());
-    assert_false(Sanitizer.defaultConfig().allowCustomElements);
-  }, "SanitizerAPI defaultConfig()");
+    assert_false("dropElements" in Sanitizer.defaultConfig);
+    assert_false("blockElements" in Sanitizer.defaultConfig);
+    assert_false("dropAttributes" in Sanitizer.defaultConfig);
+    assert_false(Sanitizer.defaultConfig.allowCustomElements);
+  }, "SanitizerAPI defaultConfig");
 
   test(t => {
-    assert_deep_equals(Sanitizer.defaultConfig(),
-                       new Sanitizer().config());
-  }, "SanitizerAPI config() on default created Sanitizer");
+    assert_deep_equals(Sanitizer.defaultConfig,
+                       new Sanitizer().config);
+  }, "SanitizerAPI config on default created Sanitizer");
 
   test(t => {
     const configs = [{
@@ -52,8 +52,8 @@
       allowCustomElements: false,
     }];
     for (const config of configs)
-      assert_deep_equals(config, new Sanitizer(config).config());
-  }, "SanitizerAPI config() reflects creation config.");
+      assert_deep_equals(config, new Sanitizer(config).config);
+  }, "SanitizerAPI config reflects creation config.");
 </script>
 </body>
 </html>