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

gpu/command_buffer/client/query_tracker.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.
 
 #ifndef GPU_COMMAND_BUFFER_CLIENT_QUERY_TRACKER_H_
 #define GPU_COMMAND_BUFFER_CLIENT_QUERY_TRACKER_H_
 
 #include <GLES2/gl2.h>
 
 #include <queue>
@@ skipping 119 matching lines @@
     GLenum target_;
     QuerySyncManager::QueryInfo info_;
     State state_;
     uint32 submit_count_;
     int32 token_;
     bool flushed_;
     uint64 client_begin_time_us_; // Only used for latency query target.
     uint32 result_;
   };
 
-  QueryTracker(MappedMemoryManager* manager);
+  explicit QueryTracker(MappedMemoryManager* manager);
   ~QueryTracker();
 
   Query* CreateQuery(GLuint id, GLenum target);
   Query* GetQuery(GLuint id);
   void RemoveQuery(GLuint id, bool context_lost);
 
  private:
   typedef gpu::hash_map<GLuint, Query*> QueryMap;
 
   QueryMap queries_;
   QuerySyncManager query_sync_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(QueryTracker);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_QUERY_TRACKER_H_