GN threading refactor

tools/gn/commands.cc

Index: tools/gn/commands.cc
diff --git a/tools/gn/commands.cc b/tools/gn/commands.cc
index e600872c431c56751a9723cbd7beba07e64f28fc..d40beab011ae1ef3efeff1f35750c56c60eaba10 100644
--- a/tools/gn/commands.cc
+++ b/tools/gn/commands.cc
@@ -4,7 +4,6 @@
 
 #include "tools/gn/commands.h"
 #include "tools/gn/item.h"
-#include "tools/gn/item_node.h"
 #include "tools/gn/label.h"
 #include "tools/gn/setup.h"
 #include "tools/gn/standard_out.h"
@@ -52,7 +51,7 @@ const Target* GetTargetForDesc(const std::vector<std::string>& args) {
   if (!setup->DoSetup())
     return NULL;
 
-  // FIXME(brettw): set the output dir to be a sandbox one to avoid polluting
+  // TODO(brettw): set the output dir to be a sandbox one to avoid polluting
   // the real output dir with files written by the build scripts.
 
   // Do the actual load. This will also write out the target ninja files.
@@ -62,8 +61,7 @@ const Target* GetTargetForDesc(const std::vector<std::string>& args) {
   // Need to resolve the label after we know the default toolchain.
   // TODO(brettw) find the current directory and resolve the input label
   // relative to that.
-  Label default_toolchain = setup->build_settings().toolchain_manager()
-      .GetDefaultToolchainUnlocked();
+  Label default_toolchain = setup->loader()->default_toolchain_label();
   Value arg_value(NULL, args[0]);
   Err err;
   Label label =
@@ -73,19 +71,14 @@ const Target* GetTargetForDesc(const std::vector<std::string>& args) {
     return NULL;
   }
 
-  ItemNode* node;
-  {
-    base::AutoLock lock(setup->build_settings().item_tree().lock());
-    node = setup->build_settings().item_tree().GetExistingNodeLocked(label);
-  }
-  if (!node) {
-    Err(Location(), "",
-        "I don't know about this \"" + label.GetUserVisibleName(false) +
-        "\"").PrintToStdout();
+  const Item* item = setup->builder()->GetItem(label);
+  if (!item) {
+    Err(Location(), "Label not found.",
+        label.GetUserVisibleName(false) + " not found.").PrintToStdout();
     return NULL;
   }
 
-  const Target* target = node->item()->AsTarget();
+  const Target* target = item->AsTarget();
   if (!target) {
     Err(Location(), "Not a target.",
         "The \"" + label.GetUserVisibleName(false) + "\" thing\n"