Remove explicit keyword from multi-argument constructors

net/disk_cache/mapped_file_unittest.cc

 // 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.
 
 #include "base/basictypes.h"
 #include "base/file_util.h"
 #include "base/string_util.h"
 #include "net/disk_cache/disk_cache_test_base.h"
 #include "net/disk_cache/disk_cache_test_util.h"
 #include "net/disk_cache/mapped_file.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 // Implementation of FileIOCallback for the tests.
 class FileCallbackTest: public disk_cache::FileIOCallback {
  public:
-  explicit FileCallbackTest(int id,
-                            MessageLoopHelper* helper,
-                            int* max_id)
+  FileCallbackTest(int id, MessageLoopHelper* helper, int* max_id)
       : id_(id),
         helper_(helper),
         max_id_(max_id) {
   }
   virtual ~FileCallbackTest() {}
 
   virtual void OnFileIOComplete(int bytes_copied);
 
  private:
   int id_;
@@ skipping 53 matching lines @@
               &completed));
   if (!completed)
     expected++;
 
   helper.WaitUntilCacheIoFinished(expected);
 
   EXPECT_EQ(expected, helper.callbacks_called());
   EXPECT_FALSE(helper.callback_reused_error());
   EXPECT_STREQ(buffer1, buffer2);
 }