Simplify devtools code on android and enable devtools for android content_shell.

content/browser/android/devtools_auth.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 "content/public/browser/android/devtools_auth.h"
+
+#include "base/logging.h"
+
+namespace content {
+
+bool CanUserConnectToDevTools(uid_t uid, gid_t gid) {
+  struct passwd* creds = getpwuid(uid);
+  if (!creds || !creds->pw_name) {
+    LOG(WARNING) << "DevTools: can't obtain creds for uid " << uid;
+    return false;
+  }
+  if (gid == uid &&
+      (strcmp("root", creds->pw_name) == 0 ||  // For rooted devices
+       strcmp("shell", creds->pw_name) == 0)) {  // For non-rooted devices
+    return true;
+  }
+  LOG(WARNING) << "DevTools: connection attempt from " << creds->pw_name;
+  return false;
+}
+
+}  // namespace content