Sort "deps" and "public_deps" when running the "gn format" command.

tools/gn/parse_tree.cc

Index: tools/gn/parse_tree.cc
diff --git a/tools/gn/parse_tree.cc b/tools/gn/parse_tree.cc
index d22adca5c4b5f2d380d1f7167a769e1ec6bb985c..a8ec4ae92c10310be73ab3731f3e1b92917f1020 100644
--- a/tools/gn/parse_tree.cc
+++ b/tools/gn/parse_tree.cc
@@ -16,6 +16,26 @@
 
 namespace {
 
+enum DepsCategory {
+  kDepsCategoryLocal = 0,

[tfarina, 2015/12/02 20:19:32]

my understanding from the style-guide is that this should be ALL_CAPS. Do you
mind changing?

[scottmg, 2015/12/02 22:12:12]

nit; Drop the " = N" since it's just for ordering purposes and they're all
default values anyway.

[sdefresne, 2015/12/03 09:30:00]

Done both (dropped = N, used ALL_CAPS).

+  kDepsCategoryRelative = 1,
+  kDepsCategoryAbsolute = 2,
+  kDepsCategoryOther = 3,
+};
+
+DepsCategory GetDepsCategory(base::StringPiece deps) {

[tfarina, 2015/12/02 20:19:32]

is it more recommended to pass it by value rather than ref-to-const?

[sdefresne, 2015/12/03 09:30:00]

base/strings/string_piece.h recommends passing by value:
// Prefer passing StringPieces by value:
//   void MyFunction(StringPiece arg);

https://code.google.com/p/chromium/codesearch#chromium/src/base/strings/strin...

+  if (deps.length() < 2 || deps[0] != '"' || deps[deps.size() - 1] != '"')
+    return kDepsCategoryOther;
+
+  if (deps[1] == ':')
+    return kDepsCategoryLocal;
+
+  if (deps[1] == '/')
+    return kDepsCategoryAbsolute;
+
+  return kDepsCategoryRelative;
+}
+
 std::tuple<base::StringPiece, base::StringPiece> SplitAtFirst(
     base::StringPiece str,
     char c) {
@@ -590,7 +610,8 @@ void ListNode::SortAsDepsList() {
   SortList([](const ParseNode* a, const ParseNode* b) {
     base::StringPiece astr = GetStringRepresentation(a);
     base::StringPiece bstr = GetStringRepresentation(b);
-    return SplitAtFirst(astr, ':') < SplitAtFirst(bstr, ':');
+    return std::make_pair(GetDepsCategory(astr), SplitAtFirst(astr, ':')) <
+           std::make_pair(GetDepsCategory(bstr), SplitAtFirst(bstr, ':'));
   });
 }