Revert 171569 as it broke some browser_tests on win_aura.

gpu/command_buffer/service/mailbox_manager.cc

 // 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.
 
 #include "gpu/command_buffer/service/mailbox_manager.h"
 
-#include <algorithm>
-
 #include "base/rand_util.h"
 #include "crypto/hmac.h"
 #include "gpu/command_buffer/service/gl_utils.h"
 #include "gpu/command_buffer/service/texture_definition.h"
 
 namespace gpu {
 namespace gles2 {
 
-MailboxName::MailboxName() {
-  std::fill(key, key + sizeof(key), 0);
-  std::fill(signature, signature + sizeof(signature), 0);
-}
-
 MailboxManager::MailboxManager()
     : hmac_(crypto::HMAC::SHA256),
       textures_(std::ptr_fun(&MailboxManager::TargetNameLess)) {
   base::RandBytes(private_key_, sizeof(private_key_));
   bool success = hmac_.Init(
       base::StringPiece(private_key_, sizeof(private_key_)));
   DCHECK(success);
-  DCHECK(!IsMailboxNameValid(MailboxName()));
 }
 
 MailboxManager::~MailboxManager() {
-  DCHECK(!textures_.size());
 }
 
 void MailboxManager::GenerateMailboxName(MailboxName* name) {
   base::RandBytes(name->key, sizeof(name->key));
   SignMailboxName(name);
 }
 
 TextureDefinition* MailboxManager::ConsumeTexture(unsigned target,
                                                   const MailboxName& name) {
   if (!IsMailboxNameValid(name))
     return NULL;
 
   TextureDefinitionMap::iterator it =
       textures_.find(TargetName(target, name));
-  if (it == textures_.end())
+  if (it == textures_.end()) {
+    NOTREACHED();
     return NULL;
+  }
 
   TextureDefinition* definition = it->second.definition.release();
   textures_.erase(it);
 
   return definition;
 }
 
 bool MailboxManager::ProduceTexture(unsigned target,
                                     const MailboxName& name,
                                     TextureDefinition* definition,
@@ skipping 63 matching lines @@
     TextureManager* owner)
     : definition(definition),
       owner(owner) {
 }
 
 MailboxManager::OwnedTextureDefinition::~OwnedTextureDefinition() {
 }
 
 }  // namespace gles2
 }  // namespace gpu