Add missing (and remove superfluous) 'explicit' from constructors.

ipc/ipc_send_fds_test.cc

 // 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.
 
 #include "build/build_config.h"
 
 #include "ipc/ipc_tests.h"
 
 #if defined(OS_MACOSX)
 extern "C" {
@@ skipping 31 matching lines @@
 
   ASSERT_EQ(close(fd), 0);
 
   // We compare iNode numbers to check that the file sent over the wire
   // was actually the same physical file as the one we were expecting.
   ASSERT_EQ(inode_num, st.st_ino);
 }
 
 class MyChannelDescriptorListener : public IPC::Listener {
  public:
-  MyChannelDescriptorListener(ino_t expected_inode_num)
+  explicit MyChannelDescriptorListener(ino_t expected_inode_num)
       : expected_inode_num_(expected_inode_num),
         num_fds_received_(0) {}
 
   virtual bool OnMessageReceived(const IPC::Message& message) {
     PickleIterator iter(message);
 
     ++num_fds_received_;
     base::FileDescriptor descriptor;
 
     IPC::ParamTraits<base::FileDescriptor>::Read(
@@ skipping 133 matching lines @@
   IPC::Channel chan(kTestClientChannel, IPC::Channel::MODE_SERVER,
                     &listener);
   ASSERT_TRUE(chan.Connect());
 
   base::ProcessHandle process_handle = SpawnChild(TEST_DESCRIPTOR_CLIENT,
                                                   &chan);
   TestDescriptorServer(chan, process_handle);
 }
 
 #endif  // defined(OS_POSIX)