Extract permission alias info from PermissionsProvider

chrome/common/extensions/chrome_aliases.cc

Index: chrome/common/extensions/chrome_aliases.cc
diff --git a/chrome/common/extensions/chrome_aliases.cc b/chrome/common/extensions/chrome_aliases.cc
new file mode 100644
index 0000000000000000000000000000000000000000..84d7fbc1861b7618f6d1a6fb159b5172834ebfdd
--- /dev/null
+++ b/chrome/common/extensions/chrome_aliases.cc
@@ -0,0 +1,33 @@
+// Copyright 2016 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 "chrome/common/extensions/chrome_aliases.h"
+
+#include "base/macros.h"

[Devlin, 2016/10/07 18:36:21]

needed?

[tbarzic, 2016/10/07 20:41:17]

yes, for arraysize.

+
+namespace extensions {
+
+namespace {
+
+struct AliasInfo {
+  const char* const alias_name;
+  const char* const real_name;
+};
+
+const AliasInfo kPermissionAliases[] = {
+    {"windows", "tabs"},
+};
+
+}  // namespace
+
+std::vector<Alias> GetChromePermissionAliases() {
+  std::vector<Alias> result;

[Devlin, 2016/10/07 18:36:21]

Why not
return {
  Alias("windows", "tabs"),
};
?

[tbarzic, 2016/10/07 20:41:17]

Main reason: it's clearer which string is alias name, and which one is real name
when parsing this file.
with return {Alias("window", "tabs")} one would have to look up alias.h to
figure out which one is alias and which one is not.

And I find writing Alias("window" /* alias_name */, "tab" /* real_name */);
for each added alias clunkier (more evident in the other file).

Though, I don't feel that strongly about it.

[Devlin, 2016/10/07 21:05:59]

But it's only clearer because you basically re-define the class as a struct in
AliasInfo - which isn't great.  To avoid the "window" /* alias name */ et al you
could just put one top-level comment above the return value:
// First value is the alias name; second value is the real name. See also
alias.h.

+  for (size_t i = 0; i < arraysize(kPermissionAliases); ++i) {
+    const AliasInfo& kAlias = kPermissionAliases[i];
+    result.push_back(Alias(kAlias.alias_name, kAlias.real_name));
+  }
+  return result;
+}
+
+}  // namespace extensions