[DevTools] Improve performance of InstrumentingAgents.

third_party/WebKit/Source/core/inspector/InstrumentingSessions.h

Index: third_party/WebKit/Source/core/inspector/InstrumentingSessions.h
diff --git a/third_party/WebKit/Source/core/inspector/InstrumentingSessions.h b/third_party/WebKit/Source/core/inspector/InstrumentingSessions.h
deleted file mode 100644
index cd7d3b3c3907afdc78be3c8c218d8e6dd3dab55a..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/core/inspector/InstrumentingSessions.h
+++ /dev/null
@@ -1,18 +0,0 @@
-// 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.
-
-#ifndef InstrumentingSessions_h
-#define InstrumentingSessions_h
-
-#include "platform/heap/Handle.h"
-#include "wtf/HashSet.h"
-
-namespace blink {
-
-class InspectorSession;
-using InstrumentingSessions = HeapHashSet<Member<InspectorSession>>;
-
-} // namespace blink
-
-#endif // !defined(InstrumentingSessions_h)