Presentation API: add UMA.

Source/modules/presentation/PresentationSession.cpp

 // Copyright 2014 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 "config.h"
 #include "modules/presentation/PresentationSession.h"
 
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMArrayBufferView.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/events/Event.h"
 #include "core/events/MessageEvent.h"
 #include "core/fileapi/FileReaderLoader.h"
 #include "core/fileapi/FileReaderLoaderClient.h"
 #include "core/frame/LocalFrame.h"
+#include "core/frame/UseCounter.h"
 #include "modules/EventTargetModules.h"
 #include "modules/presentation/Presentation.h"
 #include "modules/presentation/PresentationController.h"
 #include "modules/presentation/PresentationRequest.h"
 #include "modules/presentation/PresentationSessionConnectEvent.h"
 #include "public/platform/modules/presentation/WebPresentationSessionClient.h"
 #include "wtf/Assertions.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/text/AtomicString.h"
 
@@ skipping 121 matching lines @@
 
 const AtomicString& PresentationSession::interfaceName() const
 {
     return EventTargetNames::PresentationSession;
 }
 
 ExecutionContext* PresentationSession::executionContext() const
 {
     if (!frame())
         return nullptr;
-    return frame()->document();}
+    return frame()->document();
+}
+
+bool PresentationSession::addEventListener(const AtomicString& eventType, PassRefPtrWillBeRawPtr<EventListener> listener, bool capture)
+{
+    if (eventType == EventTypeNames::statechange)
+        UseCounter::count(executionContext(), UseCounter::PresentationSessionStateChangeEventListener);
+    else if (eventType == EventTypeNames::message)
+        UseCounter::count(executionContext(), UseCounter::PresentationSessionMessageEventListener);
+
+    return EventTarget::addEventListener(eventType, listener, capture);
+}
 
 DEFINE_TRACE(PresentationSession)
 {
     visitor->trace(m_blobLoader);
     RefCountedGarbageCollectedEventTargetWithInlineData<PresentationSession>::trace(visitor);
     DOMWindowProperty::trace(visitor);
 }
 
 const AtomicString& PresentationSession::state() const
 {
@@ skipping 180 matching lines @@
 {
     ASSERT(!m_messages.isEmpty() && m_messages.first()->type == MessageTypeBlob);
     // FIXME: generate error message?
     // Ignore the current failed blob item and continue with next items.
     m_messages.removeFirst();
     m_blobLoader.clear();
     handleMessageQueue();
 }
 
 } // namespace blink