Resource: helper class to prohibit {add,remove}Client() calls in scope

third_party/WebKit/Source/core/fetch/Resource.h

Index: third_party/WebKit/Source/core/fetch/Resource.h
diff --git a/third_party/WebKit/Source/core/fetch/Resource.h b/third_party/WebKit/Source/core/fetch/Resource.h
index b6733bbb5e5a4f4519c6f4cff58ce1b89447579b..565aef3a28cb03b4edbb6f6aba416d0c5320b326 100644
--- a/third_party/WebKit/Source/core/fetch/Resource.h
+++ b/third_party/WebKit/Source/core/fetch/Resource.h
@@ -38,6 +38,7 @@
 #include "platform/web_process_memory_dump.h"
 #include "public/platform/WebDataConsumerHandle.h"
 #include "wtf/Allocator.h"
+#include "wtf/AutoReset.h"
 #include "wtf/HashCountedSet.h"
 #include "wtf/HashSet.h"
 #include "wtf/text/WTFString.h"
@@ -363,6 +364,12 @@ class CORE_EXPORT Resource : public GarbageCollectedFinalized<Resource>,
   SharedBuffer* data() const { return m_data.get(); }
   void clearData() { m_data.clear(); }
 
+  class ProhibitAddRemoveClientInScope : public AutoReset<bool> {
+   public:
+    ProhibitAddRemoveClientInScope(Resource* resource)
+        : AutoReset(&resource->m_isAddRemoveClientProhibited, true) {}
+  };
+
  private:
   class ResourceCallback;
   class CachedMetadataHandlerImpl;
@@ -413,6 +420,8 @@ class CORE_EXPORT Resource : public GarbageCollectedFinalized<Resource>,
   bool m_isRevalidating : 1;
   bool m_isAlive : 1;
 
+  bool m_isAddRemoveClientProhibited;
+
   // Ordered list of all redirects followed while fetching this resource.
   Vector<RedirectPair> m_redirectChain;