Propagate more information about ValueStore errors to callers, notably an

chrome/browser/value_store/testing_value_store.h

 // Copyright (c) 2012 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 CHROME_BROWSER_VALUE_STORE_TESTING_VALUE_STORE_H_
 #define CHROME_BROWSER_VALUE_STORE_TESTING_VALUE_STORE_H_
 
 #include "base/compiler_specific.h"
 #include "chrome/browser/value_store/value_store.h"
 
 // ValueStore for testing, with an in-memory storage but the ability to
 // optionally fail all operations.
 class TestingValueStore : public ValueStore {
  public:
   TestingValueStore();
   virtual ~TestingValueStore();
 
-  // Sets whether to fail all requests (default is false).
-  void SetFailAllRequests(bool fail_all_requests);
+  // Sets the error code for requests. If OK, errors won't be thrown.
+  // Defaults to OK.
+  void set_error_code(ErrorCode error_code) { error_code_ = error_code; }
 
   // Accessors for the number of reads/writes done by this value store. Each
   // Get* operation (except for the BytesInUse ones) counts as one read, and
   // each Set*/Remove/Clear operation counts as one write. This is useful in
   // tests seeking to assert that some number of reads/writes to their
   // underlying value store have (or have not) happened.
   int read_count() { return read_count_; }
   int write_count() { return write_count_; }
 
   // ValueStore implementation.
   virtual size_t GetBytesInUse(const std::string& key) OVERRIDE;
   virtual size_t GetBytesInUse(const std::vector<std::string>& keys) OVERRIDE;
   virtual size_t GetBytesInUse() OVERRIDE;
   virtual ReadResult Get(const std::string& key) OVERRIDE;
   virtual ReadResult Get(const std::vector<std::string>& keys) OVERRIDE;
   virtual ReadResult Get() OVERRIDE;
   virtual WriteResult Set(
       WriteOptions options,
       const std::string& key,
       const Value& value) OVERRIDE;
   virtual WriteResult Set(
       WriteOptions options, const DictionaryValue& values) OVERRIDE;
   virtual WriteResult Remove(const std::string& key) OVERRIDE;
   virtual WriteResult Remove(const std::vector<std::string>& keys) OVERRIDE;
   virtual WriteResult Clear() OVERRIDE;
 
  private:
+  scoped_ptr<ValueStore::Error> TestingError();
+
   DictionaryValue storage_;
   int read_count_;
   int write_count_;
-  bool fail_all_requests_;
+  ErrorCode error_code_;
 
   DISALLOW_COPY_AND_ASSIGN(TestingValueStore);
 };
 
 #endif  // CHROME_BROWSER_VALUE_STORE_TESTING_VALUE_STORE_H_