gpu: Generate mailboxes on client side

gpu/command_buffer/service/mailbox_manager.cc

Index: gpu/command_buffer/service/mailbox_manager.cc
diff --git a/gpu/command_buffer/service/mailbox_manager.cc b/gpu/command_buffer/service/mailbox_manager.cc
index e2fb86f85ad47914831274c1ce396d5760cb2b0e..c337b483929bb7dea5f70ec13ba98c382afcbe37 100644
--- a/gpu/command_buffer/service/mailbox_manager.cc
+++ b/gpu/command_buffer/service/mailbox_manager.cc
@@ -21,10 +21,6 @@ MailboxManager::~MailboxManager() {
   DCHECK(textures_to_mailboxes_.empty());
 }
 
-void MailboxManager::GenerateMailbox(Mailbox* mailbox) {
-  crypto::RandBytes(mailbox->name, sizeof(mailbox->name));
-}
-
 Texture* MailboxManager::ConsumeTexture(unsigned target,
                                         const Mailbox& mailbox) {
   MailboxToTextureMap::iterator it =