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

base/timer_unittest.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 "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/timer.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using base::TimeDelta;
 
 namespace {
 
 // The message loops on which each timer should be tested.
 const MessageLoop::Type testing_message_loops[] = {
   MessageLoop::TYPE_DEFAULT,
   MessageLoop::TYPE_IO,
 #if !defined(OS_IOS)  // iOS does not allow direct running of the UI loop.
   MessageLoop::TYPE_UI,
 #endif
 };
 
 const int kNumTestingMessageLoops = arraysize(testing_message_loops);
 
 class OneShotTimerTester {
  public:
-  OneShotTimerTester(bool* did_run, unsigned milliseconds = 10)
+  explicit OneShotTimerTester(bool* did_run, unsigned milliseconds = 10)
       : did_run_(did_run),
         delay_ms_(milliseconds) {
   }
   void Start() {
     timer_.Start(FROM_HERE, TimeDelta::FromMilliseconds(delay_ms_), this,
                  &OneShotTimerTester::Run);
   }
  private:
   void Run() {
     *did_run_ = true;
@@ skipping 441 matching lines @@
                 base::Bind(&SetCallbackHappened1));
     timer.Reset();
     // Since Reset happened before task ran, the user_task must not be cleared:
     ASSERT_FALSE(timer.user_task().is_null());
     MessageLoop::current()->Run();
     EXPECT_TRUE(g_callback_happened1);
   }
 }
 
 }  // namespace