Worker: Connect UseCounter to workers and worklets

third_party/WebKit/Source/core/workers/WorkerOrWorkletGlobalScope.cpp

Index: third_party/WebKit/Source/core/workers/WorkerOrWorkletGlobalScope.cpp
diff --git a/third_party/WebKit/Source/core/workers/WorkerOrWorkletGlobalScope.cpp b/third_party/WebKit/Source/core/workers/WorkerOrWorkletGlobalScope.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..d5b54478a8d5c5f73a4801a630a7a73b443047e5
--- /dev/null
+++ b/third_party/WebKit/Source/core/workers/WorkerOrWorkletGlobalScope.cpp
@@ -0,0 +1,35 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/workers/WorkerOrWorkletGlobalScope.h"
+
+#include "core/frame/Deprecation.h"
+#include "core/inspector/ConsoleMessage.h"
+#include "core/workers/WorkerReportingProxy.h"
+#include "core/workers/WorkerThread.h"
+
+namespace blink {
+
+WorkerOrWorkletGlobalScope::WorkerOrWorkletGlobalScope()
+    : m_deprecationWarningBits(UseCounter::NumberOfFeatures) {}
+
+WorkerOrWorkletGlobalScope::~WorkerOrWorkletGlobalScope() {}
+
+void WorkerOrWorkletGlobalScope::addDeprecationMessage(
+    UseCounter::Feature feature) {
+  DCHECK_NE(UseCounter::OBSOLETE_PageDestruction, feature);
+  DCHECK_GT(UseCounter::NumberOfFeatures, feature);
+
+  // For each deprecated feature, send console message at most once
+  // per worker lifecycle.
+  if (m_deprecationWarningBits.quickGet(feature))
+    return;
+  m_deprecationWarningBits.quickSet(feature);
+  DCHECK(!Deprecation::deprecationMessage(feature).isEmpty());
+  addConsoleMessage(
+      ConsoleMessage::create(DeprecationMessageSource, WarningMessageLevel,
+                             Deprecation::deprecationMessage(feature)));

[haraken, 2016/12/05 11:37:27]

Instead of maintaining m_deprecationWarningBits per worker, can we just send
UseCounter::Feature to the main thread and use the existing UseCounter's
BitVector to prevent the message duplication?

[nhiroki, 2016/12/06 02:22:04]

I'd prefer to keep this as is because:
(1) DeprecationMessage will be printed in worker's console from worker thread,
so thread-hopping to check the existing UseCounter's BitVector could be
inefficient.
(2) Out-of-process workers (e.g., ServiceWorker) will involve inter-process
communications to count API use in Document's UseCounter and the way wouldn't be
practical.

[haraken, 2016/12/06 02:28:55]

Ah, makes sense. I was misunderstanding that the deprecation message is printed
on main thread's console.

+}
+
+}  // namespace blink