MemoryCache: Enable MemoryCache to have multiple isolated resource maps

Source/core/fetch/MemoryCache.h

Index: Source/core/fetch/MemoryCache.h
diff --git a/Source/core/fetch/MemoryCache.h b/Source/core/fetch/MemoryCache.h
index 16ff2a12a37fa3d6bcca84ff7dc70aa24ebe7d9c..4c43802cdf98ad8ee2544b0fe8c46ee8fe7bd790 100644
--- a/Source/core/fetch/MemoryCache.h
+++ b/Source/core/fetch/MemoryCache.h
@@ -169,7 +169,8 @@ public:
         TypeStatistic other;
     };
 
-    Resource* resourceForURL(const KURL&);
+    Resource* resourceForURL(const String& cacheIdentifier, const KURL&);

[Mike West, 2014/10/24 12:43:00]

If you make |cacheIdentifier| the second argument, you can make it optional, and
avoid modifications at the various call sites that don't care about SW.

[nhiroki, 2014/10/27 14:30:13]

Done.

+    WillBeHeapVector<Member<Resource>> resourcesForURL(const KURL&);
 
     void add(Resource*);
     void replace(Resource* newResource, Resource* oldResource);
@@ -178,6 +179,8 @@ public:
 
     static KURL removeFragmentIdentifierIfNeeded(const KURL& originalURL);
 
+    static String defaultCacheIdentifier();
+
     // Sets the cache's memory capacities, in bytes. These will hold only approximately,
     // since the decoded cost of resources like scripts and stylesheets is not known.
     //  - minDeadBytes: The maximum number of bytes that dead resources should consume when the cache is under pressure.
@@ -252,6 +255,8 @@ private:
 
     bool evict(MemoryCacheEntry*);
 
+    MemoryCacheEntry* getEntryForResource(const Resource*) const;
+
     static void removeURLFromCacheInternal(ExecutionContext*, const KURL&);
 
     bool m_inPruneResources;
@@ -281,7 +286,9 @@ private:
     // A URL-based map of all resources that are in the cache (including the freshest version of objects that are currently being
     // referenced by a Web page).
     typedef WillBeHeapHashMap<String, OwnPtrWillBeMember<MemoryCacheEntry>> ResourceMap;
-    ResourceMap m_resources;
+    typedef WillBeHeapHashMap<String, OwnPtrWillBeMember<ResourceMap>> ResourceMapIndex;

[Mike West, 2014/10/24 12:43:00]

Nit: These should be converted to the new `using` syntax.

[nhiroki, 2014/10/27 14:30:13]

Done.

+    ResourceMap* getResourceMap(const String& cacheIdentifier);
+    ResourceMapIndex m_resources;

[Mike West, 2014/10/24 12:43:00]

Nit: Perhaps `m_resourceMaps`, now?

[nhiroki, 2014/10/27 14:30:13]

Done.

 
 #if ENABLE(OILPAN)
     // Unlike m_allResources, m_liveResources is a set of Resource objects which