Redesign CookieStorage and Implement Leave Secure Cookie Alone

CookieStorage has been refactored to use HashMap with base domain as the
key. Values of hashmap is vector of cookies.
CookieStorage now has max_per_host which restricts maximum cookies that
can be added per base domain.
Cookie eviction doesnot take place if max_per_host is not reached.
Cookie eviction logic implemented here does following steps
1) Evict all expired cookies
2) Remove oldest accessed non-secure cookie If any
3) When no non-secure cookie exist, remove oldest accessed secure cookie
if new cookie being added is secure. Else ignore new cookie

components/net/http_loader.rs

@@ -79,7 +79,7 @@ impl HttpState {
     pub fn new() -> HttpState {
         HttpState {
             hsts_list: Arc::new(RwLock::new(HstsList::new())),
-            cookie_jar: Arc::new(RwLock::new(CookieStorage::new())),
+            cookie_jar: Arc::new(RwLock::new(CookieStorage::new(150))),
             auth_cache: Arc::new(RwLock::new(AuthCache::new())),
             blocked_content: Arc::new(None),
         }