Reland "Move MemoryCache implementation details out of Resource"

LayoutTests/http/tests/inspector/network/cached-resource-destroyed-too-big-discarded.html

Index: LayoutTests/http/tests/inspector/network/cached-resource-destroyed-too-big-discarded.html
diff --git a/LayoutTests/http/tests/inspector/network/cached-resource-destroyed-too-big-discarded.html b/LayoutTests/http/tests/inspector/network/cached-resource-destroyed-too-big-discarded.html
index 2fd1111ea304081b80b265e9a1643a6e5c6e9f50..ed9014fd70ed80e9ee9e806d9172eab0700fd52d 100644
--- a/LayoutTests/http/tests/inspector/network/cached-resource-destroyed-too-big-discarded.html
+++ b/LayoutTests/http/tests/inspector/network/cached-resource-destroyed-too-big-discarded.html
@@ -33,11 +33,6 @@ function secondImageLoaded()
     console.log("Done2.");
 }
 
-function forceCachedResourceLoaderGC() {
-    if (window.internals)
-        window.internals.garbageCollectDocumentResources();
-}
-
 function test()
 {
     var imageRequest;
@@ -77,9 +72,6 @@ function test()
 
     function step6()
     {
-        // Force CachedResourceLoader garbage collector run.
-        InspectorTest.evaluateInPage("forceCachedResourceLoaderGC()");
-
         // Re-request content now that CachedResource should have been destroyed.
         delete imageRequest._content;
         imageRequest.requestContent(step7);