Remove modules/filesystem/DraggedIsolatedFileSystem.h dependency from core/DEPS.

Source/modules/filesystem/DraggedIsolatedFileSystem.cpp

Index: Source/modules/filesystem/DraggedIsolatedFileSystem.cpp
diff --git a/Source/modules/filesystem/DraggedIsolatedFileSystem.cpp b/Source/modules/filesystem/DraggedIsolatedFileSystem.cpp
index e0abfdc218bcb1dd7bec7faf75867095425e387a..7f0e01cc7e2055b74f283c447e9837eceb74ba46 100644
--- a/Source/modules/filesystem/DraggedIsolatedFileSystem.cpp
+++ b/Source/modules/filesystem/DraggedIsolatedFileSystem.cpp
@@ -43,12 +43,14 @@ DraggedIsolatedFileSystem::~DraggedIsolatedFileSystem()
 {
 }
 
-DOMFileSystem* DraggedIsolatedFileSystem::getDOMFileSystem(ExecutionContext* executionContext)
+DOMFileSystem* DraggedIsolatedFileSystem::getDOMFileSystem(DataObject* host, ExecutionContext* executionContext)
 {
-    ASSERT(!m_filesystemId.isEmpty());
-    if (!m_filesystem)
-        m_filesystem = DOMFileSystem::createIsolatedFileSystem(executionContext, m_filesystemId);
-    return m_filesystem.get();
+    DraggedIsolatedFileSystem* draggedIsolatedFileSystem = from(host);
+    if (!draggedIsolatedFileSystem)
+        return 0;
+    if (!draggedIsolatedFileSystem->m_filesystem)
+        draggedIsolatedFileSystem->m_filesystem = DOMFileSystem::createIsolatedFileSystem(executionContext, host->filesystemId());
+    return draggedIsolatedFileSystem->m_filesystem.get();
 }
 
 // static
@@ -63,9 +65,9 @@ DraggedIsolatedFileSystem* DraggedIsolatedFileSystem::from(DataObject* dataObjec
     return static_cast<DraggedIsolatedFileSystem*>(WillBeHeapSupplement<DataObject>::from(dataObject, supplementName()));
 }
 
-DraggedIsolatedFileSystem::DraggedIsolatedFileSystem(const String& filesystemId)
-    : m_filesystemId(filesystemId)
+DraggedIsolatedFileSystem::DraggedIsolatedFileSystem(DataObject& host, const String& filesystemId)
 {
+    host.setFilesystemId(filesystemId);
 }
 
 void DraggedIsolatedFileSystem::trace(Visitor* visitor)