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

gpu/command_buffer/client/gles2_implementation.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_GLES2_IMPLEMENTATION_H_
 #define GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_
 
 #include <GLES2/gl2.h>
 
 #include <map>
@@ skipping 310 matching lines @@
     GLuint bound_texture_2d;
 
     // texture currently bound to this unit's GL_TEXTURE_CUBE_MAP with
     // glBindTexture
     GLuint bound_texture_cube_map;
   };
 
   // Checks for single threaded access.
   class SingleThreadChecker {
    public:
-    SingleThreadChecker(GLES2Implementation* gles2_implementation);
+    explicit SingleThreadChecker(GLES2Implementation* gles2_implementation);
     ~SingleThreadChecker();
 
    private:
     GLES2Implementation* gles2_implementation_;
   };
 
   // Gets the value of the result.
   template <typename T>
   T GetResultAs() {
     return static_cast<T>(GetResultBuffer());
@@ skipping 282 matching lines @@
 
 inline bool GLES2Implementation::GetTexParameterivHelper(
     GLenum /* target */, GLenum /* pname */, GLint* /* params */) {
   return false;
 }
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_