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

content/browser/renderer_host/text_input_client_mac_unittest.mm

 // 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.
 
 #import "content/browser/renderer_host/text_input_client_mac.h"
 
 #include "base/bind.h"
 #include "base/message_loop.h"
 #include "base/threading/thread.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
@@ skipping 72 matching lines @@
 
   base::Thread thread_;
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 
 // Helper class that Start()s and Stop()s a thread according to the scope of the
 // object.
 class ScopedTestingThread {
  public:
-  ScopedTestingThread(TextInputClientMacTest* test) : thread_(test->thread_) {
+  explicit ScopedTestingThread(TextInputClientMacTest* test)
+      : thread_(test->thread_) {
     thread_.Start();
   }
   ~ScopedTestingThread() {
     thread_.Stop();
   }
 
  private:
   base::Thread& thread_;
 };
 
@@ skipping 119 matching lines @@
 TEST_F(TextInputClientMacTest, TimeoutSubstring) {
   NSAttributedString* string = service()->GetAttributedSubstringFromRange(
       widget(), NSMakeRange(0, 32));
   EXPECT_EQ(nil, string);
   EXPECT_EQ(1U, ipc_sink().message_count());
   EXPECT_TRUE(ipc_sink().GetUniqueMessageMatching(
       TextInputClientMsg_StringForRange::ID));
 }
 
 }  // namespace content