Add an eviction mechanism for SDCH dictionaries.

chrome/browser/net/sdch_browsertest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // End-to-end SDCH tests.  Uses the embedded test server to return SDCH
 // results
 
 #include "base/base64.h"
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 592 matching lines @@
   void UnsubscribeFromAllSdchNotifications() {
     DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 
     for (auto it = fetch_counts_.begin(); it != fetch_counts_.end(); ++it)
       it->first->RemoveObserver(this);
 
     fetch_counts_.clear();
   }
 
   // SdchObserver
+  void OnDictionaryUsed(net::SdchManager* manager,
+                        const std::string& server_hash) override {}
+
   void OnGetDictionary(net::SdchManager* manager,
                        const GURL& request_url,
                        const GURL& dictionary_url) override {
     DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
     DLOG(ERROR) << "Retrieving count of notifications from manager " << manager;
     DCHECK(fetch_counts_.end() != fetch_counts_.find(manager));
     ++fetch_counts_[manager];
   }
+
   void OnClearDictionaries(net::SdchManager* manager) override {}
 
   // URLFetcherDelegate
   void OnURLFetchComplete(const net::URLFetcher* source) override {
     url_fetch_complete_ = true;
     if (waiting_)
       base::MessageLoopForUI::current()->Quit();
   }
 
   SdchResponseHandler response_handler_;
@@ skipping 59 matching lines @@
   ASSERT_TRUE(SetupIncognitoBrowser());
   ASSERT_TRUE(ForceSdchDictionaryLoad(incognito_browser()));
 
   // Data fetches on main browser should not be SDCH encoded.
   bool sdch_encoding_used = true;
   ASSERT_TRUE(GetData(&sdch_encoding_used));
   EXPECT_FALSE(sdch_encoding_used);
 }
 
 }  // namespace