Remove some unused includes in headless/

Bug: 
Change-Id: Icb5351bb6112fc89e36dab82c15f32887dab9217
Reviewed-on: https://chromium-review.googlesource.com/720594
Reviewed-by: David Vallet <dvallet@chromium.org>
Commit-Queue: Iris Uy <irisu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509313}
bool HeadlessDevToolsManagerDelegate::HandleCommand(
    content::DevToolsAgentHost* agent_host,
    int session_id,
    base::DictionaryValue* command) {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);

  if (!browser_)
    return false;

  int id;
  std::string method;
  if (!command->GetInteger("id", &id) || !command->GetString("method", &method))
    return false;

  const base::DictionaryValue* params = nullptr;
  command->GetDictionary("params", &params);

  auto find_it = command_map_.find(method);
  if (find_it == command_map_.end()) {
    find_it = unhandled_command_map_.find(method);
    if (find_it != unhandled_command_map_.end())
      find_it->second.Run(agent_host, session_id, id, params);
    return false;
  }

  if (method.find("Browser.") == 0 &&
      agent_host->GetType() != content::DevToolsAgentHost::kTypeBrowser)
    return false;

  auto cmd_result = find_it->second.Run(agent_host, session_id, id, params);
  if (!cmd_result)
    return false;
  agent_host->SendProtocolMessageToClient(session_id,
                                          ToString(std::move(cmd_result)));
  return true;
}

bool HeadlessDevToolsManagerDelegate::HandleCommand(
    content::DevToolsAgentHost* agent_host,
    int session_id,
    base::DictionaryValue* command) {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);

  if (!browser_)
    return false;

  int id;
  std::string method;
  if (!command->GetInteger("id", &id) || !command->GetString("method", &method))
    return false;

  const base::DictionaryValue* params = nullptr;
  command->GetDictionary("params", &params);

  auto find_it = command_map_.find(method);
  if (find_it == command_map_.end()) {
    find_it = unhandled_command_map_.find(method);
    if (find_it != unhandled_command_map_.end())
      find_it->second.Run(agent_host, session_id, id, params);
    return false;
  }

  if (method.find("Browser.") == 0 &&
      agent_host->GetType() != content::DevToolsAgentHost::kTypeBrowser)
    return false;

  auto cmd_result = find_it->second.Run(agent_host, session_id, id, params);
  if (!cmd_result)
    return false;
  agent_host->SendProtocolMessageToClient(session_id,
                                          ToString(std::move(cmd_result)));
  return true;
}
