Add HttpCache histograms focussed on blocking and transaction type.

net/http/mock_http_cache.h

 // Copyright (c) 2011 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.
 
 // This is a mock of the http cache and related testing classes. To be fair, it
 // is not really a mock http cache given that it uses the real implementation of
 // the http cache, but it has fake implementations of all required components,
 // so it is useful for unit tests at the http layer.
 
 #ifndef NET_HTTP_MOCK_HTTP_CACHE_H_
@@ skipping 78 matching lines @@
   bool delayed_;
   static bool cancel_;
   static bool ignore_callbacks_;
 };
 
 class MockDiskCache : public disk_cache::Backend {
  public:
   MockDiskCache();
   virtual ~MockDiskCache();
 
+  virtual net::CacheType GetCacheType() const OVERRIDE;
   virtual int32 GetEntryCount() const OVERRIDE;
   virtual int OpenEntry(const std::string& key, disk_cache::Entry** entry,
                         const net::CompletionCallback& callback) OVERRIDE;
   virtual int CreateEntry(const std::string& key, disk_cache::Entry** entry,
                           const net::CompletionCallback& callback) OVERRIDE;
   virtual int DoomEntry(const std::string& key,
                         const net::CompletionCallback& callback) OVERRIDE;
   virtual int DoomAllEntries(const net::CompletionCallback& callback) OVERRIDE;
   virtual int DoomEntriesBetween(
       const base::Time initial_time,
@@ skipping 122 matching lines @@
  private:
   int Result() { return fail_ ? net::ERR_FAILED : net::OK; }
 
   disk_cache::Backend** backend_;
   net::CompletionCallback callback_;
   bool block_;
   bool fail_;
 };
 
 #endif  // NET_HTTP_MOCK_HTTP_CACHE_H_