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

chrome/browser/google_apis/base_operations.h

 // 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.
 //
 // This file provides base classes used to implement operations for Google APIs.
 
 #ifndef CHROME_BROWSER_GOOGLE_APIS_BASE_OPERATIONS_H_
 #define CHROME_BROWSER_GOOGLE_APIS_BASE_OPERATIONS_H_
 
 #include <string>
@@ skipping 76 matching lines @@
                               public OperationRegistry::Operation,
                               public net::URLFetcherDelegate {
  public:
   // AuthenticatedOperationInterface overrides.
   virtual void Start(const std::string& access_token,
                      const std::string& custom_user_agent,
                      const ReAuthenticateCallback& callback) OVERRIDE;
   virtual base::WeakPtr<AuthenticatedOperationInterface> GetWeakPtr() OVERRIDE;
 
  protected:
-  explicit UrlFetchOperationBase(
+  UrlFetchOperationBase(
       OperationRegistry* registry,
       net::URLRequestContextGetter* url_request_context_getter);
   // Use this constructor when you need to implement operations that take a
   // drive file path (ex. for downloading and uploading).
   // |url_request_context_getter| is used to initialize URLFetcher.
   // TODO(satorux): Remove the drive file path hack. crbug.com/163296
   UrlFetchOperationBase(
       OperationRegistry* registry,
       net::URLRequestContextGetter* url_request_context_getter,
       OperationType type,
@@ skipping 146 matching lines @@
 
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<GetDataOperation> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(GetDataOperation);
 };
 
 }  // namespace google_apis
 
 #endif  // CHROME_BROWSER_GOOGLE_APIS_BASE_OPERATIONS_H_