DevTools: reduce ResourceAgent dependency on PageAgent.

Source/core/inspector/EditedResourcesContentManager.h

+// 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.
+
+#ifndef EditedResourcesContentManager_h
+#define EditedResourcesContentManager_h
+
+#include "platform/heap/Handle.h"
+#include "wtf/Forward.h"
+#include "wtf/HashMap.h"
+#include "wtf/text/StringHash.h"
+#include "wtf/text/WTFString.h"
+
+namespace blink {
+
+class EditedResourcesContentManager : public NoBaseWillBeGarbageCollectedFinalized<EditedResourcesContentManager> {
+    WTF_MAKE_NONCOPYABLE(EditedResourcesContentManager);
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
+public:
+    static PassOwnPtrWillBeRawPtr<EditedResourcesContentManager> create();
+    ~EditedResourcesContentManager();
+
+    void clear();
+    void add(const String& url, const String& content);
+    bool get(const String& url, String* content);
+
+private:
+    EditedResourcesContentManager();
+
+    HashMap<String, String> m_editedResourceContent;
+};
+
+} // namespace blink
+
+#endif // EditedResourcesContentManager_h