Add pause/resume functionality to precache

components/precache/core/fetcher_pool.h

 // Copyright 2016 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.
 
 #ifndef COMPONENTS_PRECACHE_CORE_FETCHER_POOL_H_
 #define COMPONENTS_PRECACHE_CORE_FETCHER_POOL_H_
 
 #include <memory>
 #include <unordered_map>
 
@@ skipping 49 matching lines @@
 
   // Deletes all the elements in the pool.
   void DeleteAll() { elements_.clear(); }
 
   // Returns true iff the pool is empty.
   bool IsEmpty() const { return elements_.empty(); }
 
   // Returns true iff the pool can accept a new element.
   bool IsAvailable() const { return max_size_ > elements_.size(); }
 
+  const std::unordered_map<const T*, std::unique_ptr<T>>& elements() const {
+    return elements_;
+  }
+
  private:
   const size_t max_size_;
   std::unordered_map<const T*, std::unique_ptr<T>> elements_;
 
   DISALLOW_COPY_AND_ASSIGN(FetcherPool);
 };
 
 }  // namespace precache
 
 #endif  // COMPONENTS_PRECACHE_CORE_FETCHER_POOL_H_