Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

content/browser/cache_storage/cache_storage_cache_unittest.cc

Index: content/browser/cache_storage/cache_storage_cache_unittest.cc
diff --git a/content/browser/cache_storage/cache_storage_cache_unittest.cc b/content/browser/cache_storage/cache_storage_cache_unittest.cc
index 88363a7c4d910dc55512b8ad02fd2a51723b6de4..c1a8ccf1a3b5e5f63d6b78cc0d7faf1fb0c9168d 100644
--- a/content/browser/cache_storage/cache_storage_cache_unittest.cc
+++ b/content/browser/cache_storage/cache_storage_cache_unittest.cc
@@ -91,6 +91,13 @@ class DelayableBackend : public disk_cache::Backend {
                        const CompletionCallback& callback) override {
     return backend_->DoomEntriesSince(initial_time, callback);
   }
+  int CalculateSizeOfEntriesBetween(
+      base::Time initial_time,
+      base::Time end_time,
+      const CompletionCallback& callback) override {
+    return backend_->CalculateSizeOfEntriesBetween(
+        initial_time, end_time, callback);
+  }
   scoped_ptr<Iterator> CreateIterator() override {
     return backend_->CreateIterator();
   }