Add a scoping object to help block scripting during plugin destruction.

Source/web/WebReentrantScriptForbiddenScope.cpp

Index: Source/web/WebReentrantScriptForbiddenScope.cpp
diff --git a/Source/modules/webaudio/testing/InternalsWebAudio.cpp b/Source/web/WebReentrantScriptForbiddenScope.cpp
similarity index 51%
copy from Source/modules/webaudio/testing/InternalsWebAudio.cpp
copy to Source/web/WebReentrantScriptForbiddenScope.cpp
index 631b8abb2f75a26a595a1d7bd6926f237171dc23..5823f4ab984166d7c62ff6597bc3bbff15b6837c 100644
--- a/Source/modules/webaudio/testing/InternalsWebAudio.cpp
+++ b/Source/web/WebReentrantScriptForbiddenScope.cpp
@@ -3,15 +3,15 @@
 // found in the LICENSE file.
 
 #include "config.h"
-#include "modules/webaudio/testing/InternalsWebAudio.h"
+#include "public/web/WebReentrantScriptForbiddenScope.h"
 
-#include "modules/webaudio/AudioNode.h"
+#include "platform/ReentrantScriptForbiddenScope.h"
 
 namespace blink {
 
-unsigned InternalsWebAudio::audioHandlerCount(Internals& internals)
+bool WebReentrantScriptForbiddenScope::isForbidden()
 {
-    return AudioHandler::instanceCount();
+    return ReentrantScriptForbiddenScope::isForbidden();
 }
 
 } // namespace blink