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

chrome/browser/signin/oauth2_token_service_unittest.cc

 // Copyright 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/stringprintf.h"
 #include "chrome/browser/signin/oauth2_token_service.h"
 #include "chrome/browser/signin/oauth2_token_service_factory.h"
 #include "chrome/browser/signin/token_service_factory.h"
 #include "chrome/browser/signin/token_service_unittest.h"
 #include "chrome/common/chrome_notification_types.h"
@@ skipping 44 matching lines @@
   std::string last_token_;
   int number_of_correct_tokens_;
   GoogleServiceAuthError last_error_;
   int number_of_errors_;
 };
 
 // A testing consumer that retries on error.
 class RetryingTestingOAuth2TokenServiceConsumer
     : public OAuth2TokenService::Consumer {
  public:
-  RetryingTestingOAuth2TokenServiceConsumer(
+  explicit RetryingTestingOAuth2TokenServiceConsumer(
       OAuth2TokenService* oauth2_service)
       : oauth2_service_(oauth2_service),
         number_of_correct_tokens_(0),
         last_error_(GoogleServiceAuthError::None()),
         number_of_errors_(0) {}
   virtual ~RetryingTestingOAuth2TokenServiceConsumer() {}
 
   virtual void OnGetTokenSuccess(const OAuth2TokenService::Request* request,
                                  const std::string& token,
                                  const base::Time& expiration_date) OVERRIDE {
@@ skipping 416 matching lines @@
   EXPECT_EQ(1, consumer.number_of_errors_);
 
   fetcher = factory_.GetFetcherByID(0);
   EXPECT_TRUE(fetcher);
   fetcher->set_response_code(net::HTTP_UNAUTHORIZED);
   fetcher->SetResponseString("");
   fetcher->delegate()->OnURLFetchComplete(fetcher);
   EXPECT_EQ(0, consumer.number_of_correct_tokens_);
   EXPECT_EQ(2, consumer.number_of_errors_);
 }