Support deprecation warnings in shared/service workers

Source/core/workers/WorkerGlobalScope.cpp

Index: Source/core/workers/WorkerGlobalScope.cpp
diff --git a/Source/core/workers/WorkerGlobalScope.cpp b/Source/core/workers/WorkerGlobalScope.cpp
index 6d6a901ca86fe65db42f79609be6d214c6e2da06..d3d560afee320e7c239610a51d8aab30405939b6 100644
--- a/Source/core/workers/WorkerGlobalScope.cpp
+++ b/Source/core/workers/WorkerGlobalScope.cpp
@@ -334,9 +334,21 @@ void WorkerGlobalScope::countFeature(UseCounter::Feature) const
     // FIXME: How should we count features for shared/service workers?
 }
 
-void WorkerGlobalScope::countDeprecation(UseCounter::Feature) const
+void WorkerGlobalScope::countDeprecation(UseCounter::Feature feature) const
 {
     // FIXME: How should we count features for shared/service workers?
+

[sof, 2015/02/05 08:48:18]

Could you add a comment (or an assert, if you prefer) making it clear what kinds
of global scopes are handled here?

[Kunihiko Sakamoto, 2015/02/05 10:35:37]

Done.

+    // For each deprecated feature, send console message at most once
+    // per worker lifecycle.
+    if (!m_deprecationWarningBits) {
+        m_deprecationWarningBits = adoptPtr(new BitVector(UseCounter::NumberOfFeatures));
+        m_deprecationWarningBits->clearAll();
+    }
+    if (!m_deprecationWarningBits->quickGet(feature)) {
+        m_deprecationWarningBits->quickSet(feature);
+        ASSERT(!UseCounter::deprecationMessage(feature).isEmpty());
+        executionContext()->addConsoleMessage(ConsoleMessage::create(DeprecationMessageSource, WarningMessageLevel, UseCounter::deprecationMessage(feature)));

[sof, 2015/02/05 08:48:18]

We know currently from calling context that executionContext() will be valid,
but could you add an assert?

[Kunihiko Sakamoto, 2015/02/05 10:35:37]

Done.

+    }
 }
 
 ConsoleMessageStorage* WorkerGlobalScope::messageStorage()