WebCore's MemoryCache will reuse main resources when bugs.webkit.org/show_bug.cgi?id=105667 lands. However, there are some concerns with turning this on for chromium. Because of how chromium selects which process to use to load a given page and which callbacks trigger those decisions, it's not 100% clear whether crucial checks will be skipped when a resource is loaded from MemoryCache. Bug 105667 will probably land with main resource caching disabled for chromium, so this bug will track the chromium-specific stuff.