Revert 171569 as it broke some browser_tests on win_aura.

gpu/command_buffer/service/mailbox_manager.cc

Index: gpu/command_buffer/service/mailbox_manager.cc
===================================================================
--- gpu/command_buffer/service/mailbox_manager.cc	(revision 171661)
+++ gpu/command_buffer/service/mailbox_manager.cc	(working copy)
@@ -4,8 +4,6 @@
 
 #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"
@@ -14,11 +12,6 @@
 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)) {
@@ -26,11 +19,9 @@
   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) {
@@ -45,8 +36,10 @@
 
   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);