Prepare to add more initiator info to CachedResource(Request)

Source/core/loader/cache/CachedResourceLoader.h

Index: Source/core/loader/cache/CachedResourceLoader.h
diff --git a/Source/core/loader/cache/CachedResourceLoader.h b/Source/core/loader/cache/CachedResourceLoader.h
index 0794a86b64c76d55c7f5b74c3c80a50a16b699a2..274b9da844c68a8e383338e23533611252c54417 100644
--- a/Source/core/loader/cache/CachedResourceLoader.h
+++ b/Source/core/loader/cache/CachedResourceLoader.h
@@ -29,6 +29,7 @@
 #include "core/loader/cache/CachePolicy.h"
 #include "core/loader/cache/CachedResource.h"
 #include "core/loader/cache/CachedResourceHandle.h"
+#include "core/loader/cache/CachedResourceInitiatorInfo.h"
 #include "core/loader/cache/CachedResourceRequest.h"
 #include "core/platform/Timer.h"
 #include "core/platform/network/ResourceLoadPriority.h"
@@ -174,12 +175,6 @@ private:
 
     Timer<CachedResourceLoader> m_garbageCollectDocumentResourcesTimer;
 
-    struct InitiatorInfo {
-        AtomicString name;
-        double startTime;
-    };
-    HashMap<CachedResource*, InitiatorInfo> m_initiatorMap;
-
     // 29 bits left
     bool m_autoLoadImages : 1;
     bool m_imagesEnabled : 1;