Convert plugin and GPU process to brokered handle duplication.

BUG=119250
Review URL: https://chromiumcodereview.appspot.com/9958034

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@132303 0039d316-1c4b-4281-b951-d872f2087c98
CommandBufferProxyImpl::~CommandBufferProxyImpl() {
  for (TransferBufferMap::iterator it = transfer_buffers_.begin();
       it != transfer_buffers_.end();
       ++it) {
    delete it->second.shared_memory;
    it->second.shared_memory = NULL;
  }
}

CommandBufferProxyImpl::~CommandBufferProxyImpl() {
  for (TransferBufferMap::iterator it = transfer_buffers_.begin();
       it != transfer_buffers_.end();
       ++it) {
    delete it->second.shared_memory;
    it->second.shared_memory = NULL;
  }
}
