[net] Better StopCaching() handling for HttpCache::Transaction.

net/http/mock_http_cache.h

Index: net/http/mock_http_cache.h
diff --git a/net/http/mock_http_cache.h b/net/http/mock_http_cache.h
index 632bb3e63c16996290e5ed945c6d7f7909eea5c0..7d53cd828b5bd29893c414df4a351fc4262e2006 100644
--- a/net/http/mock_http_cache.h
+++ b/net/http/mock_http_cache.h
@@ -137,6 +137,10 @@ class MockDiskCache : public disk_cache::Backend {
   // Returns number of times a cache entry was successfully created.
   int create_count() const { return create_count_; }
 
+  // Resets open_count() and create_count(). Calling this is recommended to
+  // reset the counts after test setup.
+  void ResetCounts();
+
   // Fail any subsequent CreateEntry and OpenEntry.
   void set_fail_requests() { fail_requests_ = true; }
 
@@ -195,6 +199,9 @@ class MockHttpCache {
   // Wrapper to fail request conditionalization for new transactions.
   void FailConditionalizations();
 
+  // Reset the transaction and operation counts.
+  void ResetCounts();
+
   // Helper function for reading response info from the disk cache.
   static bool ReadResponseInfo(disk_cache::Entry* disk_entry,
                                HttpResponseInfo* response_info,