Allow immutable textures into mailboxes

gpu/command_buffer/service/texture_manager.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_SERVICE_TEXTURE_MANAGER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_TEXTURE_MANAGER_H_
 
 #include <vector>
 #include "base/basictypes.h"
 #include "base/hash_tables.h"
@@ skipping 152 matching lines @@
 
     void SetStreamTexture(bool stream_texture) {
       stream_texture_ = stream_texture;
     }
 
     int IsStreamTexture() {
       return stream_texture_;
     }
 
     void SetImmutable(bool immutable) {
-      DCHECK(!immutable_);
       immutable_ = immutable;
     }
 
     bool IsImmutable() {
       return immutable_;
     }
 
     // Whether a particular level/face is cleared.
     bool IsLevelCleared(GLenum target, GLint level);
 
@@ skipping 351 matching lines @@
   // The default textures for each target (texture name = 0)
   TextureInfo::Ref default_textures_[kNumDefaultTextures];
 
   DISALLOW_COPY_AND_ASSIGN(TextureManager);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_TEXTURE_MANAGER_H_