Re-enable ReportingObserver and make noop (#24726)

browser/test/disabled_features/reporting_observer_browsertest.cc

@@ -32,11 +32,11 @@ class ReportingObserverTest : public InProcessBrowserTest {
   }
 };
 
-IN_PROC_BROWSER_TEST_F(ReportingObserverTest, IsDisabled) {
+IN_PROC_BROWSER_TEST_F(ReportingObserverTest, IsNoop) {
   GURL url = embedded_test_server()->GetURL(kReportingObserver);
   ASSERT_TRUE(ui_test_utils::NavigateToURL(browser(), url));
   content::WebContents* contents =
       browser()->tab_strip_model()->GetActiveWebContents();
 
-  EXPECT_EQ(true, EvalJs(contents, "isReportingObserverDisabled();"));
+  EXPECT_EQ(true, EvalJs(contents, "isReportingObserverNoop();"));
 }

chromium_src/third_party/blink/renderer/core/context_features/context_feature_settings.h

@@ -1,30 +0,0 @@
-/* Copyright (c) 2020 The Brave Authors. All rights reserved.
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this file,
- * You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#ifndef BRAVE_CHROMIUM_SRC_THIRD_PARTY_BLINK_RENDERER_CORE_CONTEXT_FEATURES_CONTEXT_FEATURE_SETTINGS_H_
-#define BRAVE_CHROMIUM_SRC_THIRD_PARTY_BLINK_RENDERER_CORE_CONTEXT_FEATURES_CONTEXT_FEATURE_SETTINGS_H_
-
-// ContextEnabled=ReportingObservers feature methods need to be added since we
-// patched ReportingObservers as ContextEnabled into
-// third_party/blink/renderer/core/frame/reporting_observer.idl
-#define BRAVE_CONTEXT_FEATURE_SETTINGS_H_      \
- public:                                       \
-  void enableReportingObservers(bool enable) { \
-    enable_reporting_observers_ = enable;      \
-  }                                            \
-  bool isReportingObserversEnabled() const {   \
-    return enable_reporting_observers_;        \
-  }                                            \
-                                               \
- private:                                      \
-  bool enable_reporting_observers_ = false;    \
-                                               \
- public:
-//  #define BRAVE_CONTEXT_FEATURE_SETTINGS_H_
-
-#include "src/third_party/blink/renderer/core/context_features/context_feature_settings.h"  // IWYU pragma: export
-#undef BRAVE_CONTEXT_FEATURE_SETTINGS_H_
-
-#endif  // BRAVE_CHROMIUM_SRC_THIRD_PARTY_BLINK_RENDERER_CORE_CONTEXT_FEATURES_CONTEXT_FEATURE_SETTINGS_H_

chromium_src/third_party/blink/renderer/core/frame/reporting_observer.cc

@@ -0,0 +1,19 @@
+/* Copyright (c) 2024 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "third_party/blink/renderer/core/frame/reporting_observer.h"
+
+#define QueueReport QueueReport_Unused
+#include "src/third_party/blink/renderer/core/frame/reporting_observer.cc"
+#undef QueueReport
+
+namespace blink {
+
+// Don't add reports. We previously used to disable ReportingObserver in
+// Brave, but for webcompat reasons, we now just no-op it. This makes
+// takeRecords() always return an empty list.
+void ReportingObserver::QueueReport(Report* report) {}
+
+}  // namespace blink

chromium_src/third_party/blink/renderer/core/frame/reporting_observer.h

@@ -0,0 +1,17 @@
+/* Copyright (c) 2024 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef BRAVE_CHROMIUM_SRC_THIRD_PARTY_BLINK_RENDERER_CORE_FRAME_REPORTING_OBSERVER_H_
+#define BRAVE_CHROMIUM_SRC_THIRD_PARTY_BLINK_RENDERER_CORE_FRAME_REPORTING_OBSERVER_H_
+
+#define QueueReport                   \
+  QueueReport_Unused(Report* report); \
+  void QueueReport
+
+#include "src/third_party/blink/renderer/core/frame/reporting_observer.h"  // IWYU pragma: export
+
+#undef QueueReport
+
+#endif  // BRAVE_CHROMIUM_SRC_THIRD_PARTY_BLINK_RENDERER_CORE_FRAME_REPORTING_OBSERVER_H_

patches/third_party-blink-renderer-core-context_features-context_feature_settings.h.patch

@@ -1,12 +0,0 @@
-diff --git a/third_party/blink/renderer/core/context_features/context_feature_settings.h b/third_party/blink/renderer/core/context_features/context_feature_settings.h
-index 096d49ecd53d7e17811ad7d70ea6a9b2af9acd6f..eed64a36e45779db4a16e75f40b02b76b480673a 100644
---- a/third_party/blink/renderer/core/context_features/context_feature_settings.h
-+++ b/third_party/blink/renderer/core/context_features/context_feature_settings.h
-@@ -64,6 +64,7 @@ class CORE_EXPORT ContextFeatureSettings final
-   }
- 
-   void Trace(Visitor*) const override;
-+  BRAVE_CONTEXT_FEATURE_SETTINGS_H_
- 
-  private:
-   bool enable_mojo_js_ = false;

patches/third_party-blink-renderer-core-frame-reporting_observer.idl.patch

@@ -1,12 +0,0 @@
-diff --git a/third_party/blink/renderer/core/frame/reporting_observer.idl b/third_party/blink/renderer/core/frame/reporting_observer.idl
-index 90d04d7f35828629d71124cdd0024baebd7d4fb3..094d82aa0d3ba6b70c112907c94edc49f1003506 100644
---- a/third_party/blink/renderer/core/frame/reporting_observer.idl
-+++ b/third_party/blink/renderer/core/frame/reporting_observer.idl
-@@ -7,6 +7,7 @@
- callback ReportingObserverCallback = void (sequence<Report> reports, ReportingObserver observer);
- 
- [
-+    ContextEnabled=ReportingObservers,
-     ActiveScriptWrappable,
-     Exposed=(Window,Worker)
- ] interface ReportingObserver {

test/data/reporting_observer.html

@@ -1,11 +1,21 @@
 <script>
-  function isReportingObserverDisabled() {
+  function isReportingObserverNoop() {
     try {
-      new ReportingObserver(function(reports, observer) {
-      	return false;
-	  }, {});
-    } catch (err) {
-      return true;
+      const observer = new ReportingObserver(() => {},
+        { types: ['deprecation'], buffered: true }
+      );
+      observer.observe();
+      const xhr = new XMLHttpRequest();
+      // false makes it synchronous, which is deprecated.
+      xhr.open('GET', '/', false);
+      xhr.send(null);
+      const reports = observer.takeRecords();
+      console.log("Reports:", reports);
+      // Even though we made a synchronous request, we should not have any reports.
+      return reports.length === 0;
+    } catch (error) {
+      console.error("Error occurred:", error);
+      return false;
     }
   }
 </script>