Remove explicit keyword from multi-argument constructors

chrome/browser/sync/engine/syncapi.h

 // Copyright (c) 2011 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 defines the "sync API", an interface to the syncer
 // backend that exposes (1) the core functionality of maintaining a consistent
 // local snapshot of a hierarchical object set; (2) a means to transactionally
 // access and modify those objects; (3) a means to control client/server
 // synchronization tasks, namely: pushing local object modifications to a
 // server, pulling nonlocal object modifications from a server to this client,
@@ skipping 576 matching lines @@
 };
 
 // Sync API's WriteTransaction is a read/write BaseTransaction.  It wraps
 // a syncable::WriteTransaction.
 //
 // NOTE: Only a single model type can be mutated for a given
 // WriteTransaction.
 class WriteTransaction : public BaseTransaction {
  public:
   // Start a new read/write transaction.
-  explicit WriteTransaction(const tracked_objects::Location& from_here,
-                            UserShare* share);
+  WriteTransaction(const tracked_objects::Location& from_here,
+                   UserShare* share);
   virtual ~WriteTransaction();
 
   // Provide access to the syncable.h transaction from the API WriteNode.
   virtual syncable::BaseTransaction* GetWrappedTrans() const;
   syncable::WriteTransaction* GetWrappedWriteTrans() { return transaction_; }
 
  protected:
   WriteTransaction() {}
 
   void SetTransaction(syncable::WriteTransaction* trans) {
@@ skipping 461 matching lines @@
  private:
   // An opaque pointer to the nested private class.
   SyncInternal* data_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncManager);
 };
 
 }  // namespace sync_api
 
 #endif  // CHROME_BROWSER_SYNC_ENGINE_SYNCAPI_H_